Dietary Guidelines Advisory Committee Meeting
Sponsored by the
U.S. Department of Health and Human Services (HHS)
U.S. Department of Agriculture (USDA)
Held at the
Hubert Humphrey Building, Room 800
200 Independence Avenue, SW
September 23-24, 2003
Tuesday, September 23
Dietary Guidelines Advisory Committee: Dr. Janet C. King
(Chair), Dr. Lawrence J. Appel, Dr. Yvonne L. Bronner, Dr. Benjamin
Caballero, Dr. Carlos A. Camargo, Dr. Fergus M. Clydesdale, Dr. Vay
Liang W. Go, Dr. Penny M. Kris-Etherton , Dr. Joanne R. Lupton, Dr.
Theresa A. Nicklas, Dr. Russell R. Pate (attended September 24), Dr.
F. Xavier Pi-Sunyer, Dr. Connie M. Weaver
Executive Secretaries: Ms. Carole Davis, Ms. Kathryn McMurry,
Dr. Pamela Pehrsson, Dr. Karyl Thomas Rattay,
Others: HHS Secretary Tommy G. Thompson, Mr. Eric Bost, Dr.
Cristina Beato, Ms. Carter Blakey, Dr. Linda Meyers, Dr. Eric Hentges
Welcome and Introduction of the Committee
Dr. Cristina Beato, Acting Assistant Secretary for Health, HHS,
welcomed participants to the first meeting of the 2005 Dietary
Guidelines Advisory Committee on behalf of Secretaries Tommy Thompson
and Ann Veneman. She noted that the Dietary Guidelines, issued
jointly by the two departments since 1980, serve as a cornerstone of
Federal nutrition policy and are considered a gold standard for
science-based consumer nutrition. They also serve as a vehicle for the
government to speak with one voice on nutrition and health promotion.
Dr. Beato noted that Congress has mandated that the Dietary
Guidelines be reviewed every five years and that the Advisory
Committee will review the scientific literature and recommend changes
to the 2000 Dietary Guidelines as necessary. Ultimately the
goal is better health through food choices and physical activity.
Dr. Beato introduced the members of the 2005 Dietary Guidelines
Advisory Committee (DGAC) and thanked them for volunteering their
valuable time and services to assist HHS and USDA. She then introduced
Eric Bost, Under Secretary for Food, Nutrition and Consumer Services
at USDA. She acknowledged the close collaboration between HHS and USDA
under Secretaries Thompson and Veneman and Under Secretary Bost.
Review of the Committee Assignment/Charge to the
Eric Bost, Under Secretary for Food, Nutrition and Consumer
Services, passed on greetings from Secretary Veneman, who could
not attend because of responsibilities associated with clean up after
Hurricane Isabel. He noted that the Services’ 15 nutrition programs
collectively reach one out of every five Americans. He recognized the
challenging responsibility facing the 2005 DGAC and that the impact of
their work would be felt not only in the United States, but also
around the world. He presented the charge to the Committee about its
critical role and responsibility to the American people, and to the
Secretaries of HHS and USDA.
He then read the charge to the DGAC:
The Committee, whose duties are solely advisory and time-limited,
Examine the 2000 Edition of the Dietary Guidelines in
relation to current scientific and medical knowledge on the
relationship between diet and health.
Determine whether compelling evidence exists that warrants
revision of the 10 statements or accompanying text, which we refer
to collectively as the Dietary Guidelines.
If the Committee decides that no changes are necessary, the
Committee will so inform the Secretaries of the Departments. This
action will terminate the Dietary Advisory Guidelines Committee.
If the Committee decides that changes are warranted, based on
the preponderance of the scientific and medical knowledge, the
Committee will determine what issues for change need to be
The focus of the Committee should be on the review of the new
The Committee shall make and submit its technical
recommendations and the rationale for these recommendations in a
report to the Secretaries. The Committee’s focus should be its
recommendations and the supporting science rather than translating
the recommendations into a communication document.
Upon the submittal of the Committee’s recommendations, the
Dietary Guidelines Advisory Committee will be terminated.
Swearing In of the Committee
Tommy G. Thompson, Secretary of the Department of Health and Human
Services, thanked Dr. Beato and Mr. Bost for their work and recognized
Secretary Veneman’s strong support and close collaboration. He also
welcomed and thanked the DGAC members for volunteering their time to
promote health and prevent disease.
Secretary Thompson stressed that the guiding principle of the
Department—prevention, prevention, prevention—reinforces the critical
role that nutrition and exercise play. His job as HHS Secretary is to
ensure that Americans are strong, healthy, and independent.
Encouraging healthy habits is key. Many want to eat healthier, but are
confused about how to do so. HHS has been working to provide more
information to consumers, such as ensuring that trans fat be
listed on food labels. This has stimulated some companies to change
their manufacturing processes. Working to improve people’s
understanding of how to combine foods to make nutritious meals is also
needed. The Committee’s independent evaluation of current nutrition
science, and recommendations about healthy eating and physical
activity, will assist the two Departments in their efforts.
Secretary Thompson briefly summarized some of the statistics that
show the need for prevention efforts. For example, 125 million
Americans have one or more chronic diseases, and 75% of the health
budget of $1.4 trillion goes to treat chronic illnesses in America.
Many diseases can be prevented by making healthy lifestyle choices.
Tobacco-related illness results in 400,000 deaths per year and an
annual cost of approximately $155 billion. Type 2 diabetes results in
200,000 deaths per year and $132 billion spent yearly. And fastest
growing is obesity, on which $117 billion is spent yearly on related
illnesses and is associated with 300,000 deaths annually in this
President Bush’s HealthierUS Initiative was recently launched and
is based on four pillars:
Daily physical activity
Diet consistent with the Dietary Guidelines for Americans
Preventive medical screenings
Making healthy choices
In response to that directive, HHS has created Steps to a
HealthierUS, an initiative that helps Americans realize that even
small steps can make a dramatic difference in good health and
prevention of chronic disease.
Secretary Thompson concluded by expressing his confidence in the
DGAC and asking members to raise their right hands as he administered
the oath of office.
Dr. Beato reviewed the "rules of engagement" of the DGAC in
keeping with the Federal Advisory Committee Act to ensure an open,
Public comment must go to the full committee; therefore, all
communications to the committee must go through staff.
Written comments from the public are accepted throughout the
process. They should be clear and concise, with the scientific
justification presented along with views.
If committee members are contacted by the public, they should
refer the comments to the staff.
She then turned the meeting over to Dr. Janet C. King, Chair of the
Review of Agenda
Janet C. King, Chair, Dietary Guidelines Advisory Committee,
said she spoke on behalf of the Committee in recognizing both the
challenges and the important role that the Committee plays in the
field of nutrition. Committee members are pleased to have been
selected and are looking forward to working together. She then
reviewed the agenda for the rest of the day.
Carter Blakey, Acting Director of the Office of Disease Prevention
and Health Promotion, reviewed housekeeping details and noted that
minutes of the meeting would be posted within 60 days at
www.health.gov/dietaryguidelines. Documents pertaining to committee
deliberations would be available for public inspection and copying in
Room 738-G. Those interested should call 202-690-7102 to schedule an
Historical Overview of the Dietary Guidelines
Dr. Linda Meyers, Director Designate of the Food and Nutrition
Board of the Institute of Medicine, introduced her presentation
with the hope that putting the past in context might help chart the
future. She acknowledged the input of Michael McGinnis, whose
experience with the Dietary Guidelines stretches back many years. She
said that he usually began a historical presentation by observing that
the first attempt at dietary guidelines began with the Greeks. In
1894, W.O. Atwater made the observation that Americans’ diets should
consist of 15% calories from protein, 33% from fat, and 52% from
carbohydrates. The four food groups were presented in the 1950s.
However, the real impetus behind the Dietary Guidelines began in
the 1970s with the growing recognition that disease caused by nutrient
deficiency was less common and that diet plays a role in reducing the
risk of chronic diseases. In 1977, the Senate Select Committee on
Nutrition and Human Needs set quantitative goals, which was met with a
lot of debate.
In response, Julius Richmond, then Surgeon General and Assistant
Secretary for Health, asked Jules Hirsch, a leader in the American
Society for Clinical Nutrition, to put together a panel to look at the
literature. Their results were published in a 1979 article in the
American Journal of Clinical Nutrition. It was also drawn on for
the Surgeon General’s Healthy People report, which talked about the
relationship between diet and disease in general terms but without
guidelines or quantitative goals.
The question arose about the feasibility of issuing dietary
guidelines so that the government could speak with one voice. At a
meeting attended by representatives from USDA and the Department
of Health, Education, and Welfare (HEW, now HHS), the consensus was that
the effort to develop a single voice of dietary advice was worth
doing. Michael McGinnis and Mark Hegsted were tasked with making it
In 1980, a 20-page brochure was published that listed seven
guidelines. The lore is that final agreements were hammered out at
someone’s dining room table. This 1980 edition was presented as the
best consensus of the National Institutes of Health, the Food and Drug
Administration, and USDA. Then-Agriculture Secretary Bob Bergland,
described the Dietary Guidelines as a call for moderation, rather than
a prescription. It received extensive media attention. Subsequently,
the Senate Committee on Appropriations put in language to establish a
committee to review the scientific evidence and recommend revisions.
For the 1985 edition, a committee of nine people was charged with
the task of reviewing the latest scientific information, determining
if additions or modifications were appropriate, reviewing public
comment, and making recommendations, backed with scientific
references, to the Secretaries. The 1985 Dietary Guidelines had
two main changes from 1980: (1) "ideal" was changed to "desirable"
weight; and (2) "alcohol" was changed to "alcoholic beverages."
In 1987, Congressional language requested review of the Dietary
Guidelines on a regular basis. At the time, which Federal agency had
the lead for nutrition was somewhat contentious. To make clear that it
was a joint effort between the two Departments, joint Executive
Secretaries were appointed, and decisions about who to appoint to the
committee were made jointly.
For the 1990 Dietary Guidelines, the Committee had the same charge
of reviewing the previous Dietary Guidelines and recommending changes
if necessary. Since 1985, several consensus reports had been issued to
help in their task. The Committee recommended a diet with no more than
30% of calories from fat. (Dr. Meyers, while acknowledging that the
precise wording was significant at the time, did not recall what the
exact language was.) In addition, a more positive tone was used
throughout the Dietary Guidelines, and more advice and tips for
implementation were presented. The 1990 Dietary Guidelines also
defined healthy weight and presented a quantitative definition of
moderate drinking. Like all others, it was a policy piece and was also
used to give advice to consumers.
The National Nutrition Monitoring and Related Research Act of 1990
mandated the publishing of Dietary Guidelines every five years
Provide nutrition and dietary information
Be based on the preponderance of scientific and medical
Be promoted in any Federal food, nutrition, or health program.
The process for the 1995 Dietary Guidelines also relied on
an advisory committee and co-executive secretaries from the two
Federal departments. It put more emphasis on the beneficial aspects of
physical activity and of fruits and vegetables. It also took a more
positive tone regarding alcoholic beverages, and was the first to
highlight the Food Guide Pyramid and the role of nutrition labels as
useful educational tools.
The 2000 Dietary Guidelines presented 10 guidelines, adding
one on food safety and one on physical activity. It grouped the
guidelines in an A (Aim), B (Build), C (Choose) format. Key resources
included the 1996 Surgeon General’s Report on Physical Activity and
Health, 1998 Clinical Guidelines on the Identification,
Evaluation, and Treatment of Overweight and Obesity, and the 1997
and 1998 Dietary Reference Intake (DRI) reports.
Although the process has evolved over time, there have been some
The Dietary Guidelines have been reviewed every five years
USDA and HHS have jointly issued them
Scientific advisory committee has been charged to review them
Science-based guidance has been produced
Explanation of the rationale has become increasingly detailed
One voice in dietary guidance policy has resulted
The Dietary Guidelines have served as the framework for
additional materials by the government and others.
As the 2005 DGAC begins work, Dr. Meyers noted that it is now well
accepted that diet and disease risk are linked. She noted that new
demands on people’s time, new ways of receiving information, and an
epidemic of obesity are newer challenges. She concluded that the
Committee’s advice and wise voice about health and dietary patterns
When asked, Dr. Meyers described how the 2005 DGAC might direct its
efforts. She noted that the last three Committees found it difficult
to think about how to communicate the science to consumers. Coming up
with clear messages based on the best science will be a challenge, and
dissemination of the report in meaningful ways has always been a
When asked whether there has ever been an effort to rethink the
process and boil down the Dietary Guidelines to two or three messages,
she responded that every committee has questioned whether a simpler
way existed. She noted that the public record from 1990 and 1995
contained discussions about breaking out the Dietary Guidelines in
Dietary Guidelines’ Role in Nutrition Programs and
Food Guide Pyramid Reassessment Update
Dr. Eric Hentges, Director, Center for Nutrition Policy and
Promotion, first reviewed how the Dietary Guidelines have
influenced policy and programs in government, with the public, and in
He presented many examples of the influence of the Dietary
Guidelines over the past 22 years. They cast a big shadow by:
Forming Federal nutrition policy
Setting research agendas in science, including behavioral and
consumer science, and production and food processing
Guiding education programs and the government to speak in one
voice about nutrition
Providing a framework for public debate on nutrition and health.
A vast audience is influenced and has a stake in the Dietary
Guidelines, including policy makers, nutrition and health educators,
health care providers and organizations, industry, the media, and
consumers. Citing sodium as an example, he noted that the research
agenda is also influenced. Healthy People 2010, the National Health
and Nutrition Examination Survey (NHANES), and the Healthy Eating
Index all rely on aspects of the Dietary Guidelines. Two of the four
pillars of President Bush’s HealthierUS Initiative directly
relate to the Dietary Guidelines, as do many other initiatives
and USDA’s food assistance programs. The Dietary Guidelines also help
direct product development, food processing, food marketing, and as
public-private collaborations and partnerships.
Dr. Hentges then shifted to the topic of the ongoing reassessment
of the Food Guide Pyramid. He noted that food guidance has a long
history at USDA, dating from 1916, to the latest revision in 1992.
With new food consumption information and food composition data in the
intervening 10 years, the Food Guide Pyramid is now undergoing
In the 1980s, philosophical goals for the Food Guide were
established: to promote overall health, be based on up-to-date
research, address the total diet, be useful and realistic, refer to
commonly used foods, and be evolutionary. These goals guide the
reassessment. Three tasks are involved in the reassessment:
The technical reassessment is now in the forefront. A Notice of
Proposed Technical Updates to the Pyramid appeared in the Federal
Register (9/11/03), with the comment period under way. A summary of
the information received will be posted on the Internet and made
available to the DGAC at its second meeting. More information is
available at www.cnpp.usda.gov. Dr. Hentges clarified the two-track
process in which the revisions of the Food Guide Pyramid and of the
Dietary Guidelines are happening at the same time. Both are based
on current science.
This winter, USDA will start looking at consumer research to
determine what kind of graphic representation will best communicate
the Food Guide. Dr. Hentges expected that shortly after the 2005
Dietary Guidelines is issued, the revised food guidance will be
released. Should the DGAC change or add nutritional standards, he said
that these would be incorporated into the Food Guide graphic and that
the two documents would be in complete harmony.
Dr. Hentges concluded by noting that the Dietary Guidelines will
not only influence Federal policy and communications on nutrition and
health, but also will guide the health and well-being of all
Dr. King asked Dr. Hentges, regarding the DGAC’s role in food and
nutrition policy, whether he preferred dietary recommendations that
are more detailed and specific, or more general and overarching. Dr.
Hentges responded that they should be specific enough to direct those
who must carry them out. A host of programs depend on the clarity of
the Dietary Guidelines.
Dr. Go asked whether the scientific database developed for work on
the Food Guide Pyramid would be available to the DGAC. Dr. Hentges
noted that it would be provided to them.
When asked whether the Food Guide Pyramid itself might be changed,
Dr. Hentges responded that the question remains open, but they have
purposely separated the technical foundation from the educational
messages and the graphic representation. The bottom line is getting
people to follow the Dietary Guidelines more completely.
A short discussion ensued about avoiding discrepancies between the
two efforts. Dr. Hentges stressed that they will not set any nutrition
standards and that the Food Guide will reflect any changes or
additional standards set by the DGAC. The Food Guide is an educational
tool to communicate the Dietary Guidelines, Dietary Reference
Intakes, and other documents.
Dr. Kris-Etherton queried Dr. Hentges and Dr. Meyers about the
absence of the word "calorie" in the Dietary Guidelines,
particularly in view of the epidemic of obesity. Dr. Meyers noted that
the 2000 Dietary Guidelines refer to "healthy weight" and that
much discussion centered on wording. Ms. Kathryn McMurry, Co-Executive
Secretary who was involved with the 2000 DGAC, noted that the
intention was to be realistic and stress not gaining weight, with the
Committee recognizing that the success rates for sustained weight loss
are not high. Dr. Meyers observed that the rising numbers of obese
might imply a changed climate.
Dr. Bronner commented that one of the real issues, from a consumer
perspective, is that the Dietary Guidelines make sense and can be
implemented. Dr. Hentges replied that implementation remains the
challenge, but the influence of the Dietary Guidelines goes beyond the
document itself to the messages that can be taken from them and used
in all other programs.
Review of Timeline, Milestones, and Staff
Dr. King referred Committee members to Tab 6 of their notebooks.
Tab 6 contained a summary of the timeline and milestones under which
the Committee will operate so that if changes to the Dietary
Guidelines are deemed warranted, a report could be submitted to the
Secretaries in June 2004.
From October 2003 to January 2004, the Subcommittees, with staff
assistance, will gather information and conduct literature reviews,
prepare scientific reviews, and identify key scientific findings.
Milestones for the current meeting are deciding whether to proceed
with the scientific review and, if so, deciding upon the approach to
At the second DGAC meeting (January 2004, dates to be
scheduled), the DGAC will hear expert presentations and public
testimony (if decided upon), and receive an update on the Food Guide
Pyramid reassessment and its relationship to the revision of the
From January to March 2004, the information gathering will be
completed. Subcommittees will draft key recommendations and
rationale to present to the entire DGAC.
At the third DGAC (March 2004), the DGAC will review the
proposed key scientific recommendations and the scientific
rationale. They will work toward consensus on which recommendations
to include and which revisions need to be made.
From March to May 2004, the draft DGAC report will be prepared.
At the fourth and final DGAC meeting (May 2004), the DGAC will
review, refine and finalize the report to the Secretaries.
In June 2004, the report will be submitted to the HHS and USDA
Dr. King also referred the Committee to the list of
responsibilities of the Dietary Guidelines management team. She
praised the staff assigned to the DGAC, noting that several had worked
with past Committees.
She then reviewed the topics that would be discussed during the
afternoon (nutrient adequacy and lifecycle needs, food safety, fluid
and electrolytes, and ethanol) and the next day (carbohydrates, fatty
acids, energy balance and weight maintenance). She asked presenters to
focus on the following areas:
- What are the recent scientific advances in this area?
- What is the established science in this area?
- Where is there consensus?
- What issues need further discussion and/or further evaluation of
- What issues need additional expertise (guest speakers)?
- What issues require additional information (e.g. consumption
Nutrient Adequacy and Lifecycle Needs
Discussion Leaders: C. Weaver, T. Nicklas, Y. Bronner
Dr. Connie Weaver told the group that she recently attended the
American Society for Mineral and Bone Research (ASMBR) meeting, which
covered recent scientific and policy information and trends. She
divided her presentation into five areas:
Awareness of the escalating incidence of obesity, along with an
increase in chronic diseases such as diabetes, metabolic syndrome,
and osteoporosis. Obesity and bone health are closely related, so
that aspects of diet that are good for controlling weight are good
for bone. There has also been an increase in the number of bone
fractures in children, which has been attributed to more overweight
children falling on underdeveloped bones. The ASMBR meeting had many
posters on the inadequacy of calcium and Vitamin D in children
around the world.
The health benefits of fruits and vegetables and low-fat dairy
products have been reported through many studies. Studies to look at
include those that involve the Dietary Approaches to Stop
Hypertension (DASH) diet. The Seventh Report of the Joint National
Committee on Prevention, Detection, Evaluation, and Treatment of
High Blood Pressure (JNC 7) advocates a DASH diet to control
hypertension. The Coronary Artery Disease Risk Development in Young
Adults (CARDIA) study has looked
at a high number of subjects and the relationship between diet and
Since 2000, there were several new DRI reports, and new
information on calcium, Vitamin D, and bone. In particular, there is
now much attention on Vitamin D, including the effects of a
deficiency on special subgroups (such as those living in northern
latitudes and those with darker skins). There is an increased
incidence of rickets in babies born to mothers with inadequate
Vitamin D. Oncologists say to avoid sun to avoid skin cancer, so how
do we get adequate Vitamin D? More research on how much Vitamin D is
necessary and how that translates to diet is needed. There is also a
new DRI on fiber, and new information on the adequacy and
functionality of micronutrients such as folic acid.
Since 2000, more foods contain hidden nutrients, through
processes such as fortification. The food composition databases
cannot keep up. How do we assess whether these foods are meeting
people’s dietary needs when good databases of what the foods contain
do not exist? Questions are also raised about the bioavailability of
The public and health professionals are now more accepting of
constituents of the food supply that promote health other than the
traditionally known essential nutrients. Advances in the last five
years have emphasized liberal amounts of fruits and vegetables.
Dr. Theresa Nicklas focused on changes in food consumption
patterns among children. Using the data from the Bogalusa Heart Study,
from 1973 to 1994, there was an increase in 10-year olds’ consumption
of mixed meals (e.g. combination dishes such as lasagna and pizza),
poultry, salty snacks, fruit juice, and cheese; decrease in desserts
and candy in this study (although an increase nationally); and a
decrease in milk consumption. Recent data show that soft drink
consumption varies by region. The consumption of sweetened ice tea
drinks among children also rose in the Bogalusa study population.
Another area of concern has been portion size. The Bogalusa study
shows that total grams consumed has increased, especially in
restaurant portions. She noted that an increase from 360 to 870
calories daily, accompanied by increased sedentary activity, might
have policy implications. Using the Healthy Eating Index, 72% of
children have a diet that needs improvement and 9% have a poor diet. A
very small percentage (1%) of children are meeting the Food Guide
Pyramid recommendations. Only 5% met the recommendation for four or
more food groups, and 16% did not meet any of the Food Guide Pyramid
Average intake of most vitamins and minerals for children age 2 to
11 meet or exceed the 1989 RDAs. However, there is an increase among
children over age 11 who are not meeting the RDAs, especially for
calcium, magnesium, iron and zinc, but also other vitamins and
minerals. Dr. Nicklas then focused on calcium, noting that a similar
presentation could be made for other nutrients. At age 10, 46% of
children met the RDA for calcium. Using the current DRI (which
increases the recommended calcium intake for age 10), the percentage
decreased to 12%. Among young adults, only 25% meet the DRI of 1000 mg
daily of calcium. The percentage is lowest among African Americans and
among females in both age groups.
Fiber consumption ranges from 12.3 grams to 17.4 grams for
individuals 19 years of age and under, mostly from vegetable soups,
fruits, and fruit juices. Only a small percentage of children and
adolescents ages 2 to 18 years consume whole grains.
Among children, 50% consumed at least one food from each food group
daily. That number decreased to 19% for young adults.
A study by Kant in 2003 showed that children and adolescents who
consume the highest percentage of low nutrient-dense foods had
significantly higher total energy intake. They also consumed less
dairy, fruits and vegetables, grains, and meat or meat alternates. The
impact of dietary supplements is poorly understood. A recent study
showed that 16% of adolescents use a supplement, mostly a daily
multivitamin without minerals.
Dr. Nicklas reiterated Dr. Weaver’s concern about uncertainty about
the increasing fortification of foods and beverages. She cited one
study from Canada that showed that fortified foods led to about 10% of
men exceeding the maximum calcium intake, but not in women. This seems
to suggest that fortification is not a realistic way to meet nutrient
A final area to consider is eating patterns, including eating more
meals and snacks, and eating in restaurants more frequently.
Dr. Yvonne Bronner focused her comments on the consumer side of
the Dietary Guidelines mandate. In 2001, she and Ellen Harris wrote a
book that concluded that the average African American diet is not
meeting the Food Guide Pyramid recommendations. Using the CSFII
1994-96 database for their analysis, they found that higher income and
education did not play a role in improved diet. They looked at
consumption of fruits and vegetables, fat, and whole grains.
Dr. Bronner urged attention on how to take messages and apply them
in communities, particularly those with considerable levels of disease
and disability. She noted that overweight and obesity
disproportionately affects minority communities across all ages and
income levels. She urged recognition of the contextual environment
when applying Dietary Guidance and looking at social marketing
principles for help. For example, guidance is needed on fruit and
vegetable consumption in communities without grocery stores and where
fresh produce is difficult to obtain and to store. It comes down to
more than science. The same contextual concerns relate to physical
activity in communities with violence and without sidewalks or
In terms of needs through the life cycle, Dr. Bronner discussed the
impact of how a poor start in life might affect the onset of chronic
diseases later in life. Thus, implementation of the Dietary
Guidelines during pregnancy is important. Osteoporosis was
originally considered to be a condition that would not be of major
importance in the African American community, but it is now affecting
increasing numbers of women above age 65.
When questioned whether there is enough information to discuss
nutritional programming in pre-conception, Dr. Bronner responded that
there is enough information for the period during pregnancy, but not
Dr. Weaver asked about what data are available on tracking eating
patterns throughout life, particularly in the later years. Dr. Nicklas
noted the relationship between eating patterns and obesity. Dr.
Clydesdale recommended an article by Jim Hill in Science on
obesity. In the literature, there are a lot of associations, but
little explanation of the relationship between BMI and eating pattern
variance. In an article in Preventive Medicine, Dr. Nicklas and
colleagues looked at the association between eating patterns (e.g.,
skipping meals and snacking) and obesity. She said that there were
some associations, but these patterns could explain only 3% of BMI
Dr. Appel urged caution about methodological issues, particularly
related to the obesity epidemic, and urged looking within and across
cultures. He asked Dr. Weaver about other nutrients that were
discussed at the ASMBR meeting. In addition to Vitamin D, she reported
that there was more attention to sodium’s effect on urinary calcium
and variance by race. In terms of fruits and vegetables, the consensus
is on the need to consume more, although the exact link to bone health
is not conclusive.
Dr. Go urged examining data, particularly from the United Kingdom,
on fetal development and later diseases. Dr. King reiterated that the
Dietary Guidelines are for everyone over age 2, including pregnant and
lactating women, and to therefore keep in mind special needs. She
summed up main points from the three presentations and also asked
additional follow-up questions:
There is increased concern about Vitamin D, and this is an
In the past, bone health was linked to dairy products. This has
been expanded to include fruits and vegetables. Some studies are now
coming out that indicate that protein does not contribute to urinary
Soft drink intake has decreased in the Bogalusa cohort, but is
still high. There is concern in the literature about soft drinks as
a displacement for calcium-rich beverages.
In terms of physical activity and bone development, Dr. Weaver
said that several studies showed dramatic improvements with short
interventions early in life, but consensus hasn’t been reached about
later in life.
Dr. Nicklas said the largest gaps in nutrient adequacy seem to
be iron and zinc in females, low consumption of fruits and
vegetables and whole grains, and high consumption of low
nutrient-dense foods. Dr. Weaver added Vitamin D to the list,
although it was pointed out that sometimes consumption of Vitamin D
is poorly reported.
Although data exist on nutrients in fortified foods, Dr. Weaver
reported that changes are happening so frequently and the databases
cannot keep up.
Dr. Caballero reminded the Committee that the DRIs provide the
ability to do a group assessment through an Estimated Average
Requirement (EAR) as well as individual assessments through the RDAs.
Dr. Bronner noted that more information will be needed to document
consumption in the African American community.
USDA is doing more work on surveying fortified vs. non-fortified
foods. In terms of supplements, according to Dr. Nicklas, the few
studies on the role of dietary supplements in improved dietary
adequacy in children have some methodological limitations, but are
worth looking at.
Although it was not addressed in the 2000 Dietary Guidelines,
the importance of variety in the diet was reiterated, given the low
percentage of children who eat from all food groups. Also, portion
size cannot be ignored. Ms. McMurry reported that the 2000 DGAC also
wrestled with adequacy versus variety issues, and moved from variety
to a focus on the Food Guide Pyramid.
Dr. Penny Kris-Etherton noted the role that nutrient-dense foods
can play, especially for the elderly and children, in making sure that
they get enough nutrients even though they have decreased energy
Discussion Leader: F. Clydesdale
Dr. Fergus Clydesdale noted that a lot of research on food
safety exists in relation to industry, governments, academics, but not
restaurants or consumer behavior. It is important to have a guideline
on food safety. He noted that the current guideline is based on the
Fight BAC! program.
In a 2003 survey, consumers considered themselves at least as, or
more, responsible than manufacturers, stores and the government in
ensuring that the products they purchase from the grocery store are
safe. It would be valuable to know, Dr. Clydesdale said, whether the
2000 Dietary Guidelines contributed to that sense of
responsibility. He also said it would be valuable to know how
pathogens develop in home-based outbreaks as a way to prioritize
The International Food Information Council (IFIC) Foundation
conducted a more open-ended survey to ask consumers what food safety
issues most concern them. Food handling/ preparation and
disease/contamination were of greatest concern. The increased
attention to these topics in the media may have had an impact.
Dr. Clydesdale noted that we have enhanced detection capabilities,
and a number of tools and technologies to keep foods safe, from Hurdle
Technology to chemical dips to broadened surveillance and tracking by
regulatory agencies. However, at the end of the day "the cat is still
welcome on the table," i.e., people still will practice unsafe food
practices in their homes. A 1998 survey found that fewer than 1% of
106 U.S. and Canadian homes surveyed met the minimum criteria for
acceptable performance as outlined in the 1997 FDA Food Code for Food
Service Operations. The most frequent critical violations included
cross-contamination of food, neglected hand washing, and improper
cooling of leftovers. It would be interesting to look at the data now
to see if the 2000 Dietary Guidelines have had any effect.
Consumers must take a proactive stance in relation to keeping food
safe. They must recognize that food is not sterile, nor should it be.
Physicians have said that they welcome questions about food safety,
but usually only bring it up with special populations: patients with a
food borne illness, patients traveling abroad, immune-compromised
patients, or mothers of infants.
He also raised additional issues for the Committee to consider:
As people change their eating behaviors (he cited as an example
a colleague who ate raw tuna in a salad and was hit by a parasite),
this might have implications for the Committee’s recommendations.
The continued emergence of virulent forms of bacteria might lead
to such recommendations as not eating rare meat.
Major outbreaks in the home still coincide with those listed in
the 2000 Dietary Guidelines, with similar ways to
The 2005 Dietary Guidelines may want to incorporate
allergens, antibacterial hand cleaners and their effectiveness/risk,
supplement use, and mercury in fish.
Dr. Weaver commented that sometimes the public is unsure what they
are keeping themselves safe from. Dr. Clydesdale responded that the
Dietary Guidelines should address this more and perhaps
address different risks during the lifecycle, such as mercury in fish
as a greater concern during pregnancy.
In terms of mercury in fish, it is often a factor of where the fish
lived (farm versus wild, area of the country). There are often
conflicting messages. On the one hand, people are told about the
benefits of omega-3 and 6 fatty acids in fish, but they may also be
told to avoid fish because of mercury. A similar concern about
conflicting messages relates to allergens.
To clarify some of the issues around supplements and safety, Dr.
Clydesdale pointed Committee members to information from FDA on the
www.safety.gov Web site. Interactions
of supplements with certain foods can cause acute conditions. Dr.
Kris-Etherton also noted such concerns as statin drugs and grapefruit,
and Coumadin and vegetables high in
Although all are at risk of food borne illnesses, the elderly,
young, and immune-compromised people are at highest risk of being hit
by a pathogen perhaps resulting in death.
In a discussion about the contribution of fish oil supplements to
consuming one’s omega fatty acids, Dr. Clydesdale said that most
supplements are pretty well oxidized, and therefore, inactive.
Dr. Pi-Sunyer asked whether food safety issues are worsening,
improving, or staying the same over time. The data are not clear,
although regulatory agencies, industry, and research have contributed
to delivering a better product.
In summing up, Dr. King noted that consensus existed that food
safety should remain part of the 2005 Dietary Guidelines, as it is in
other countries. The topic of allergens should be discussed further.
Bottled water, it was felt, should not be part of the Dietary
Guidelines with their focus on the individual, rather than
government and industry.
Fluid and Electrolytes
Discussion Leader: L. Appel
Dr. Appel focused his presentation on an update of the effects of
sodium and potassium on health. He noted that the 2000 Dietary
Guidelines called for choosing and preparing food with "less" salt,
without being specific. It is generally accepted that the primary
benefit of reduced sodium intake is that it lowers blood pressure, and
thus lowers the risk of blood pressure-related conditions. Lowered
sodium intake also reduces urinary calcium excretion.
Dr. Appel referred to a number of studies:
A large 2002 meta-analysis by the Prospective Studies
Collaborative Group using 61 prospective studies that documented
direct progressive relationships between stroke and usual systolic
blood pressure and usual diastolic blood pressure in all adult age
The JNC 7 published new guidelines about what constitutes
normal, pre-hypertensive, and hypertensive levels of blood pressure.
The Framingham studies that estimate the lifetime risk of
developing hypertension as 90% for adults who reach age 50, which he
said constitutes an epidemic.
Non-pharmacologic approaches such as sodium reduction reduce blood
pressure and, indirectly, cardiovascular events. Potentially, they
prevent the age-related rise in blood pressure and could also be an
adjunct or substitute to medications. Even a small reduction in
systolic blood pressure lowers the risk for stroke mortality, coronary
heart disease (CHD), and total mortality. Dr. Appel then turned to
some of the evidence supporting sodium reduction as a means to lower
Dietary Approaches to Stop Hypertension (DASH) Sodium Trial
Trial of Hypertension Prevention (TOHP) Phase 2
International Study of Sodium, Potassium, and Blood Pressure (INTERSALT)
Trial of Nonpharmalogic Interventions in Elderly (TONE) Clinical
Dr. Appel noted that he was an investigator on the DASH Sodium
Trial, which he differentiated from the original 1997 DASH Trial. In
this feeding study, patients began with a control diet, then were
randomized so that some continued with the control diet and others
with the DASH diet of 8 to 10 servings of fruit per day, three
servings of dairy, whole grains, nuts, and fish. Overall, the DASH
diet was lower in fat than the control diet, somewhat higher in
protein, and much higher in fiber and potassium. Three sodium levels
(143 mmol/d, 106 mmol/d, and 65 mmol/d) were given to the
Blood pressure was reduced with reduced intake of sodium, both in
the control and DASH diets. Dr. Appel noted that there has been much
interest in comparing subgroups of the study—hypertensives and non-hypertensives,
African Americans and non-African Americans, and others. Sometimes it
is difficult to interpret results because of the inherent variability
of individuals’ blood pressure and how it is measured.
Dr. Appel went on to discuss the effects of one’s sodium level on
urinary calcium excretion. In both the control and DASH diets, sodium
reduction lowered urinary calcium excretion. Sodium had no effect in
LDL or HDL levels across the spectrum.
The question comes down to the feasibility of reducing sodium
intake and achieving multiple lifestyle changes. Dr. Appel noted that
in behavior intervention studies that represent optimum conditions
with motivated individuals, the TOHP study showed a reduction from 155
mmol/d to 97 mmol/d, and the TONE study showed a reduction from 144
mmol/d down to 99 mmol/d. Sodium reduction is harder to achieve when
considering multiple dietary changes.
Two major studies that have looked at the relationship between
sodium and cardiovascular disease are the NHANES Follow-up and a study
by Tuomelehto. The latter showed that a 100 mmol/d increase in urinary
sodium excretion is linked to increased coronary heart disease.
Turning to increased potassium intake, benefits include lowered
blood pressure, reduced sensitivity to the blood pressure-raising
effects of salt, and reduced calcium excretion. Key studies in this
area include a 1997 meta-analysis by Whelton (1997), a small study in
1999 by Morris, and a clinical trial that looked at reduced risk of
kidney stones by Barcelo in 1993. Morris studied 24 African Americans
and 12 non-African Americans in a crossover study with seven-day
periods that showed reduced sensitivity to sodium with increased
intake of potassium.
In response to a question about post-intervention follow-up to see
if participants maintained the lower salt diets, Dr. Appel noted that
follow-up data show recidivism. The TONE study is the best case of
changes maintained over time. Older participants on antihypertensive
medicine kept their weight off and continued with lowered sodium
intake after 2.5 years. He noted that food labeling for low sodium
products does not seem to be an effective way to reduce sodium intake
as consumers often shy away from these products. He thought it might
be better to do it quietly: for example, putting in less milligrams of
salt in a packaged food without highlighting the fact.
Looking at sodium intake for those with low blood pressure, Dr.
Appel said anecdotally, that these people might still have or develop
high blood pressure long-term.
Dr. Clydesdale remarked on the TONE results with the elderly,
particularly since older people often lose their sense of smell and
thus might want salt to increase taste. Dr. Appel observed that they
were provided with alternative flavorings (such as different spices)
and behavioral strategies to avoid salt. Practical recommendations
such as these for avoiding salt might be useful.
A very small amount of salt is needed daily to meet iodine
requirements—the equivalent of 1/4 teaspoon. Perhaps marathon runners
or others doing extreme physical activity might need to worry about
insufficient amounts, but he did not see it as a problem in the
general U.S. population. In fact, there are populations who engage in
massive physical activity, such as the Yanomamo Indians in Brazil, who
consume less than 10 mmol/d of sodium with no adverse effects.
Dr. Appel noted that, although there are no recent data, an
estimated 75% of one’s daily salt intake comes from packaged foods,
15% is added in food preparation, and 10% or less is intrinsic to the
Dr. Appel reiterated that both sodium and potassium affect blood
pressure, and that some researchers have looked at the ratio between
the two as more predictive than either amount individually. Dr. King
ended this session by noting that if hydration should be part of the
DGAC report, some additional expert information would be needed.
Discussion Leader: C. Camargo
Dr. Camargo reviewed how alcohol has been dealt with in previous
Dietary Guidelines. In 1980, language said if one drinks, do so in
moderation. In 1985, "alcohol" was changed to "alcoholic beverages,"
but the explicit call for moderation did not change. In the 2000
Dietary Guidelines, the harmful effects of excess intake
were discussed as well as some specificity about possible cardiac
benefits of consumption.
Dr. Camargo found that the studies he identified in a MEDLINE
search largely supported the 2000 Dietary Guidelines. His
suggestion was to keep the recommendations in the 2005 Dietary
Guidelines generally the same but to reorganize them slightly:
first discussing the role of alcohol in a total diet as providing few
nutrients, then addressing the harmful effects of excess and that some
people should not drink at all. The Dietary Guidelines could then
address moderation, then the potential cardiac benefits and possible
breast cancer risk. The two drinks/day for men and one drink/day for
women, he noted, should be presented as maximum recommended amounts,
Another possible area of change might be a recommendation that the
elderly (men and women) should drink no more than one alcoholic
beverage per day. In recognition of changing eating patterns, he
suggested changing "drinking with meals" to "drinking with food."
Dr. Caballero asked whether the research shows the benefits of one
type of alcoholic beverage (e.g., red wine) over others. Dr. Camargo
noted that a lot of papers have addressed the topic, but that patterns
of consumption are too confounding. People who prefer different
beverages (beer versus wine versus hard liquor) tend to have varying
demographics (such as cultural, socioeconomic and educational).
Even with one-half a drink, the cardiovascular benefits of
alcoholic beverages are seen. However, Dr. Camargo warned against
recommending or not recommending drinking, noting that the Dietary
Guidelines can suggest other alternatives than alcohol to lower
the risk of cardiovascular disease. Dr. Go questioned whether
alcohol-based substances, such as cough syrup, might be a confounding
factor, but Dr. Camargo did not feel that the discussion was necessary
in the Dietary Guidelines. More relevant, however, is concern
about alcoholic beverages interacting with some, but not all,
over-the-counter and prescription medicines.
Dr. Kris-Etherton tied the discussion about alcohol to
micronutrient levels. For example, she queried, should the DGAC
recommend not drinking if one does not have a good diet. She referred
to one study that showed that alcohol’s elevated breast cancer risk
can be eased with adequate folate consumption. Dr. Camargo noted that
saying that alcohol is empty calories addresses the nutrient issue,
but felt getting into the specifics about breast cancer would be too
confusing in such a general document. Dr. King questioned whether
alcohol promotes fat storage. Observational data show, according to
Dr. Camargo, that moderate drinkers weigh less than others. The role
of alcohol in the diet is controversial. It goes back to the
discussions about empty calories versus total calories.
Dr. Nicklas observed that the Dietary Guidelines have not been
specific about age. Dr. Camargo felt that a reorganization of the 2005
Dietary Guidelines would clarify that. We are most interested in age
limits, as well as making clear that excess for all ages is bad.
Studies over the last few years about heart benefits are vague when
referring to "younger people." However, he did say that the Committee
might want to be more specific about alcohol consumption by the
In response to a question about including a "if you don’t drink,
don’t start" message in the Dietary Guidelines, Dr. Camargo
noted that a reasonable clinician could work with a reasonable patient
but did not feel that the Dietary Guidelines should have such
Dr. Weaver brought up whether tobacco use should be addressed in
the Dietary Guidelines. Dr. King suggested the Dietary
Guidelines stay focused on diet.
Some ethnic groups have been shown not to tolerate alcohol, and the
question was raised about whether the Dietary Guidelines should
address this. Dr. Camargo thought that the Dietary Guidelines
would not have a large impact on behavior in these individuals;
rather, people with an intolerance would avoid alcohol with or without
Dr. Clydesdale asked if data existed about how many males drink two
alcoholic beverages daily, and how many females drink one. Dr. Camargo
noted that most cohorts studied tend to be moderate drinkers, many
Americans do not drink at all, and a subset drinks in excess, with the
caveat that some define "moderate" drinking as three drinks per day.
This reinforces his opinion that more specific recommendations for the
elderly might be useful in the 2005 Dietary Guidelines.
(Recess: 5:00 p.m.)
Wednesday, September 24
Dr. King opened the second day’s session by briefly reviewing key
points made in the presentations made the previous afternoon.
Nutrient Adequacy and Life Cycle Needs:
Topics of concern include the link between obesity and bone
health, Vitamin D deficiency, a new definition for fiber, an
increase in the number of fortified foods, increased interest in the
health-promoting constituents in foods, and other nutrients
important to bone health.
Regional differences in soft drink and other beverage
consumption by children exist. Children are not meeting the Food
Guide Pyramid recommendations, with the amount of iron and zinc in
girls and overall food variety of particular concern.
Increased income and education levels do not improve nutritional
intake among African Americans.
Obesity is having a disproportionate impact on minority
Established science for review include the DASH, CARDIA, and
Bogalusa studies, as well as data from the United Kingdom on fetal
development and later disease, Popkin’s studies on portion size,
USDA work on fortified foods, and an Institute of Medicine (IOM)
report on food labeling.
A consensus exists on the importance of fruits and vegetables,
as well as weight-bearing activity, on bone health.
Additional information is needed on Vitamin D deficiency; safety
and efficacy of health-promotion constituents in food; intake,
bioavailability, and safety of fortified food; children’s eating
patterns; communication of science; guidelines for pregnancy and
throughout the life cycle; the impact of carbonated beverages on
bone health, and the micronutrient density of diets.
Expertise in social marketing, life cycle issues particularly
for older adults, and food pattern development and trends would be
beneficial for the Committee.
Practical advice is needed on how to get people moving, how
children can meet the Food Guide Pyramid, and how to provide better
messages to minority populations.
- Recent scientific advances include information on whom consumers
rely for food safety information, Food Marketing Institute food
safety trends, consumer concerns data, technologies for keeping food
safe, and the survey of food safety in the home.
- The consensus is that a guideline is needed on food safety.
- Issues for further discussion include changes in consumer
behavior since release of the 2000 Dietary Guidelines and
prioritization of messages in fighting bacteria. Possible other
topics: antibacterial cleansers, allergens, supplements and
botanicals, mercury and fish oil (especially for special population
groups), and consumers’ understanding about food safety issues (or
- No additional expertise was identified as being needed.
- Additional information that would be of benefit includes the
relative risk of different geographical locations on food safety,
data related to botanicals, and food interactions.
Fluid and Electrolytes:
Recent scientific advances include recognition of the benefits
of potassium and of reduced sodium. Established science includes the
Prospective Collaborative Studies, Framingham Heart Study, DASH,
TOHP, and INTERSALT studies.
Consensus exists on the benefits of lower blood pressure and the
fact that blood pressure rises throughout one’s lifetime. Issues for
further discussion include the role of calcium and its interaction
with sodium, salt as a source of iodine, and the link between sodium
intake and cardiovascular disease.
Recent advances in understanding the benefits of potassium
include its contribution to lowering blood pressure and reduced
sensitivity to sodium intake, as well as the importance of the
Additional expertise may be needed on the topic of water
Additional information may be needed on the composition of
processed food, clarification from the 2000 Dietary Guidelines
on what "little" and "low" related to sodium intake really mean, and
practical recommendations to help consumers reduce their sodium
Recent scientific advances support the 2000 Dietary
Guidelines. Moderate drinking can lower the risk of
cardiovascular disease, but even one drink per day can increase
breast cancer risk. Moderate drinkers tend to weigh less, but
alcoholic beverages represent empty calories from a nutritional
point of view.
The current Dietary Guidelines are sufficient, but need some
reorganization and wordsmithing. Specifying moderate drinking as one
drink daily for the elderly might also be necessary.
No additional expertise was identified as necessary.
Additional information needed is on the interaction of alcohol
with the absorption of certain nutrients, compliance with the
current Guideline, and recommendations for the elderly.
Dr. King then introduced the next three topics: carbohydrates,
fatty acids, and energy balance and weight maintenance.
Discussion Leaders: J. Lupton, B.Caballero, X. Pi-Sunyer
Dr. Joanne Lupton divided her presentation into three parts: a
review of references to carbohydrates in the 2000 Dietary
Guidelines, new information that has appeared since then, and
considerations for the 2005 Dietary Guidelines.
Information about carbohydrates appears in several places in the
2000 Dietary Guidelines:
Let the Pyramid guide your food choices
Choose a variety of grains daily, especially whole grains
Choose a variety of fruits and vegetables daily
Chose beverages and foods to moderate your intake of sugars.
The Macronutrient Report has come out since the 2000 Dietary
Guidelines and four members of the DGAC served on that National
Academy of Sciences (NAS)/IOM Panel. The IOM panel reviewed all human
studies before making any conclusions related to carbohydrates. A
preliminary copy of the report has been released. Major findings
include the following:
Establishment of an Recommended Dietary Allowance (RDA) for
carbohydrates of 130 grams per day (lower for infants, higher for
pregnant and lactating women), based on the amount of glucose needed
by the brain
Establishment of an acceptable range for carbohydrates as a
percentage of calories
Recommendations on added sugar consumption
Substantial discussion on glycemic index, glycemic load, and
The report contains a chapter on fiber, including a definition of
fiber and establishment of adequate intake (AI) for fiber.
One item from the report that might influence the 2005 Dietary
Guidelines is the Acceptable Macronutrient Distribution Range (AMDR),
which the report presents as:
Carbohydrates, 45 to 65% of Kcals (If it is lower than 45%, it
is hard for an individual to meet his or her AI for fiber and it
might be offset by too high a percentage of Kcals coming from fat.
Higher than 65% may lead to hypertriglyceridemia and one’s fat or
protein intake may be too low).
Lipids, 20 to 35% of Kcals
Protein, 10 to 35% of Kcals
Dr. Lupton noted that the "added sugar" recommendation was getting
much attention. Using the USDA definition of added sugars, major
sources include soft drinks, cakes and cookies, and other sweet drinks
and snacks. The Macronutrient Report recommends at maximum, 25% of
one’s total Kcals should come from added sugar. When this 25% amount
is approximately reached, it has been shown that the intake of a
number of micronutrients decreases, including calcium, magnesium, and
The IOM Macronutrient Panel discussed glycemic index (GI), which is
essentially a classification of the effect of carbohydrate-containing
foods on blood glucose levels. The higher the GI, the more rapidly
foods are digested and metabolized, resulting in higher blood sugar
levels. Each food has a GI, such as 1.31 for carrots, 1.21 for
potatoes, 1.00 for white bread, 0.92 for sucrose, 0.86 for pizza, and
0.52 for an apple. The Panel realized that GI should not be the only
thing to consider (i.e., using this classification, pizza is better
than carrots). Instead, the Panel looked at Glycemic Load (GL), which
is the GI times the amount of carbohydrates in a serving. By this
measure, carrots have a moderate Glycemic Load, less than potatoes or
Dr. Lupton noted that a number of studies link GL with one’s
relative risk of type 2 diabetes. Those with a diet low in cereal
fiber and with a high GL, run a risk of getting type 2 diabetes that
is 2.05 times greater than those with a low GL and high-fiber diet.
More studies are looking at GL and its link with other diseases.
Although more research is needed, the Panel felt that it was important
to understand that there are differences in absorption between
carbohydrates – not all carbohydrates are created equally.
In looking at increased fiber intake, the Panel reviewed studies to
understand how fiber affects health. Surprising to many, it wasn’t as
a protection against colon cancer but against coronary heart disease,
that the strongest link was established. The AI numbers are based on
three studies: the Health Professionals Study, Nurses Study, and
Finnish Men’s study. The Panel came up with a recommendation for fiber
intake that ranged from 21 grams per day (for women over age 50) to 38
grams per day (for men under age 50). Recommendations are based on 14
grams of fiber per 1000 calories. Generally, Americans are eating
about one-half the amount of fiber that they should be.
Topics for discussion for the 2005 Dietary Guidelines:
Recommendations about added sugars
Glycemic potential of carbohydrates ("all carbohydrates are not
Do the current Dietary Guidelines and the Food Guide Pyramid
place too much emphasis on grains?
In response to a question from Dr. Weaver, Dr. Lupton noted that
the Macronutrient Report presents tables that show what foods would
help a person reach the AI for fiber. Generally, if one has a good
diet—with whole grains, fruits, and vegetables—then chances are that
enough fiber is being consumed. The IOM Panel did not look at various
weight loss diets, such as low-carbohydrate diets, and their impact on
Dr. Xavier Pi-Sunyer introduced his presentation with an
overview of some aspects of the typical American diet:
- Carbohydrates (50% of total calories):
- Starches: 17%
- Food sugars: 17% (mostly in fruit and milk)
- Added sugars: 16% (mostly in soft drinks, sweets, and fruit
The body does not recognize a carbohydrate from added sugar
differently than another carbohydrate. The issue is the low
micronutrient density of carbohydrates from added sugar so that the
body is short of some nutrients. Of the various types of added sugars,
use of high fructose corn syrup has increased in the past decade, and
higher fructose intake is related to increased triglyceride levels.
Common starch sources include: corn, tapioca, flour, pasta, and
Although fiber intake is a positive aspect of grains, especially
whole grains, the question can be asked whether we need 6 to 11
servings daily. In a population that is overeating, carbohydrates
might rise above 55% of the total food consumed daily, which might
increase triglyceride level (an independent risk factor for coronary
artery disease) and lower HDL level. In addition, some people might
substitute carbohydrates for monounsaturated fats. Although there are
populations around the world that consume a higher percentage of
carbohydrates than Americans, their total caloric intake is lower.
Dr. Pi-Sunyer presented a hypothesis stating that high glucose
leads to higher insulin levels, which can lead to increased food
intake, increase β-cell exhaustion and
diabetes, and lead to insulin resistance and coronary artery disease.
However, he noted that this remains a hypothesis only. Observational
studies show that increased insulin resistance leads to diabetes.
There have not been long-term interventional studies of
He noted that consuming more fiber could solve a lot of issues
related to glycemic index. By eating more fruits, vegetables and whole
grains, a person is consuming more fiber and a lower GI diet.
Dr. Benjamin Caballero was the final presenter of the
Carbohydrates session and also was a member of the IOM Macronutrient
Panel. Although the mandate of the DGAC is to recommend guidelines for
healthy individuals, he questioned how to deal with the majority of
Americans who have a Body Mass Index (BMI) above 25. He suggested
tackling this issue in the context of energy balance.
Regarding protein, Dr. Caballero reported that the scientific basis
for dietary recommendations has not changed much, and are still based
on nitrogen balance studies. Some specific issues for further research
include the protein requirements of the elderly and of infants. The
body of knowledge is not sufficient to replace the traditional
approach of nitrogen balance in considering protein intake.
Discussion first centered on the recommendation to increase fiber
intake. Dr. Lupton noted that the IOM Macronutrient Panel’s
recommendation was based on grams of fiber per 1,000 calories. It is a
relative proportion so that those eating few calories (such as small
children) would eat less fiber. Many children are not meeting the DRI
for carbohydrates, Dr. Nicklas noted, and she asked for the rationale
behind the notion that "there is too much emphasis on carbohydrates in
the Pyramid." Dr. Lupton noted that most Americans are getting about
52% of their calories from carbohydrates and are thus falling within
the AMDR range.
The Committee also discussed a measurement issue: different fruits
have different GI levels, and even different pieces of a specific
fruit, such as a banana, can differ based on different levels of
fructose content. Mixed meals also present a challenge, since most of
the measurements have been made on isolated carbohydrates.
The Macronutrient report devotes a chapter to translating its
findings. It includes information on diets, physical activity, good
food sources, and other information. Carbohydrates cannot be looked at
in isolation, but in relation to the total diet. In terms of
translating the science, Dr. Caballero reminded the Committee that the
DRI process uses committee to come up with implementation suggestions,
and IOM has commissioned a book to condense the DRI reports into one
volume for dietitians and health professionals.
Turning back to fiber, Dr. Lupton was asked about the effect of all
one’s fiber coming from an isolated source, rather than throughout the
diet. Fiber is divided into two parts: dietary fiber from food and
functional fiber (part of the new definition) from plant extractions
or laboratory synthesis. Getting all one’s fiber from functional fiber
would not give the same overall benefits. Data on how people are
consuming fiber and other nutrients in the various food groups (for
example, pasta versus cereals versus rice) would be useful to examine.
The sources of carbohydrates, not just totals, are important to
From an epidemiological point of view, Dr. Camargo reminded the
Committee that various study designs are being examined. In some
cases, randomized trials are urged, but in other cases, they do not
seem as necessary.
(Break: 10:15 to 10:30)
Discussion Leaders: T. Nicklas, P. Kris-Etherton, V.L.W. Go
Dr. Theresa Nicklas presented an overview of what is known
about fat intake, particularly in children. Over the past two decades,
the percentage of the total diet from proteins and carbohydrates has
increased, and from fat has decreased. The Continuing Survey of Food
Intakes by Individuals (CSFII) data from 1994, 1996, and 1998 show
that children ages 6 to 11 consume 14% daily from proteins, 55% from
carbohydrates, and 33% from fat. In terms of fatty acids, about 12% is
saturated fat, 13% is monounsaturated fat (MUFA), and 6%-12% is
polyunsaturated fat (PUFA).
The new DRIs recommend a total of 20 to 35% fat daily, with lowered
amounts of saturated fat. The issue is how to maintain moderate fat
intake and also increase unsaturated fatty acids and maintain a
balance between monounsaturated fat and polyunsaturated fat. She
raised two questions:
- Are there optimal levels for monounsaturated fat and
polyunsaturated fat that should be recommended?
- Should upper intakes for these two types of fatty acids be
Little has been published about how children consume their
monounsaturated fats. The Bogalusa data show that consumption of MUFA
decreased in children over 20 years from 14% to 12% and PUFA
consumption increased. There are a wide variety of food sources of
MUFA for children ages 6 to 11, including: peanut butter, potatoes as
French fries, dairy products, salty snacks, and meat products. Asians
and Pacific Islanders have the lowest MUFA intake and African
Americans have the highest. MUFA intake increases up to age 19, and
then stabilizes. Regionally, it is lowest in the Northeast, highest in
the South among children, and highest in the Midwest after age 19.
The American Heart Association’s Scientific Advisory and
Coordinating Committee recommends eating a variety of fish at least
twice a week to get omega-3 fatty acids, as well as flaxseed, canola
oils, and other foods rich in alpha-linolenic acid. However, this
brings in the discussion related to mercury and food safety.
Trans fat has recently been the subject of a number of studies.
The Nurses Health Study, for example, showed that trans fatty
acids were linked to increased coronary artery disease in women. There
has also been a lot of discussion about fat and added sugars in
Americans’ diets. The CSFII study indicates that 45% of school-aged
children’s caloric intake comes from discretionary fat (defined as the
top part of the Food Guide Pyramid) and added sugars combined.
Finally, Dr. Nicklas recommended that the DGAC address the issue of
Dr. Penny Kris-Etherton summarized the current recommendations
made by various groups that go beyond the Dietary Guidelines,
including the DRI Macronutrient Panel, American Diabetes Association,
National Heart, Lung, and Blood Institute’s Third Report of the
National Cholesterol Education Program Expert Panel on Detection,
Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult
Treatment Panel III) (NHLBI/NCEP-ATP III), the Dietary Guidelines
for Americans, and American Heart Association (AHA) Guidelines.
Most recommend that fat intake range between 20 and 35%, with those
less than 30% for weight control and reduction. NAS is not specific
about the amount of saturated fat ("low as possible"); the others
generally recommend less than 10%. They each deal with other types of
fat in slightly different manners.
Dr. Kris-Etherton suggested that the DGAC address the issues of
trans fat and omega-3 fatty acids closely. There has been much
research and interest on these two topics.
The AI recommendation by NAS on the ratio between omega-6 and
omega-3 fatty acids is around 10 or 11. She suggested referring to WHO
and FAO recommendations on this. The United States is consistent with
other countries in terms of recommendations for this ratio, with
Sweden’s recommendations slightly higher, and Japan’s appreciably
higher. The American Heart Association published guidelines on omega-3
intake using several studies conducted since 2000. Their
recommendations were as follows:
For patients without documented CHD: Eat a variety of
(preferably oily) fish at least twice a week, and oils rich in
alpha-linolenic acid (ALA) (such as flaxseed, walnuts, soybean and
For patients with documented CHD: 1 gram of Eicosapentaenoic
Acid (EPA) and Docosahexaenoic
Acid (DHA) per day, preferably from oily fish, or through
supplements in consultation with a physician.
For patients needing triglyceride lowering: 2 to 4 grams of EPA
+ DHA per day, provided as capsules under a physician’s care.
However, a recent study has challenged the "omega-3 dogma",’ which
she said merited a careful look. Dr. Burr et al. has shown that
omega-3 supplements and fish did not help men with angina, but had
adverse effects. She noted that the study must be reviewed carefully.
Within the context of what is implementable, Dr. Kris-Etherton
presented a table from the DRI report that showed how low fat could go
and still meet the recommendations for omega-3 and omega-6 fatty acid
intake. She also shared the AHA’s major guidelines to achieve a
healthy overall diet, healthy weight, desirable lipid levels, and
desirable blood pressure. Their guidelines are food-based, rather than
based on percentages of various macronutrients and micronutrients.
She concluded by pointing to five issues for consideration by the
New risk factor criteria for cardiovascular disease (CVD),
diabetes, and hypertension leading to lower recommended levels for
BMI and glucose;
New evidence showing that lowering the major risk factors can do
away with 80 to 90% of heart disease;
The role of trans fat, omega-3 fatty acids,
monounsaturated fat, and stearic acid in the diet;
Developing an ideal fatty acid profile and an optimum fat to
Communicating the "fat" message to the public. Now they have
heard about "good" and "bad" fats, and many are overdoing fats just
as several years ago, people were overdoing low-fat,
Dr. Vay Liang W. Go added final comments on fatty acids.
The first issue was on fat substitutes and lipid inhibitors and their
impact on absorption of micronutrients. The last DGAC did not address
the relationship between fat and cancer, as there was no conclusive
evidence at that time. Now the Committee can look at the American
Institute for Cancer Research criteria related to diet and cancer
prevention. One of the largest ongoing global studies is the European
Prospective Investigation into Cancer and Nutrition (EPIC), with which
the National Cancer Institute has had interaction. Within the United
States, there are data from the Women’s Health Initiative, Women’s
Nutrition Intervention Studies, and others.
Normal parameters of what constitutes "healthy" are being lowered.
Normal blood pressure used to be considered 140/90; now it is 120/80.
The BMI level considered healthy has been lowered to 25. What is
considered a normal parameter for a lipid profile is also changing.
Finally, he underscored the importance of translating findings so the
public can use them.
There are no long-term data, but some data is available on olestra
from the FDA.
One of the persistent beliefs remains that "eating fat makes you
fat." Dr. Camargo noted many studies show that a low-fat diet leads to
weight loss, but the loss cannot be maintained. Issues such as satiety
and the ability to stay on the diet come into play. A balance needs to
be drawn between saying that fat is not so bad and avoiding a
boomerang effect with people consuming too much.
The emphasis perhaps needs to be on total calories. In countries
where people are generally leaner, they are eating fewer calories.
Thus, for example, they are able to eat larger percentages of
carbohydrates without the risk of higher triglyceride levels.
There is a fair amount of epidemiological evidence linking omega-3
fatty acids and decreased risk of disease. Dr. Kris-Etherton referred
to a study that showed a lower risk of sudden death and arrhythmia.
When it appeared that some studies showed a positive effect and some
showed none, one investigator sorted the information by looking at
people at high risk and those at lower risk. Then the data were
clearer that high-risk people benefited from omega-3 fatty acids.
The role of stored fats in weight change after pregnancy and the
impact on lactation is an area to be looked at.
The risks versus benefits of fish, given mercury levels, are now
being studied at the Harvard Center for Risk Analysis.
Level of physical activity has an effect on overall caloric intake.
The proportions of macronutrients needed might vary depending where a
person is on the physical activity continuum. Given this, Dr. Pate
queried if the DGAC recommendations should be segmented depending on
how active a person is, particularly those who are sedentary. However,
it is not clear how much data there are on dietary limitations for the
The role of genetics in disease, and thus the resulting
recommendations for diet, are being studied, but Dr. Pi-Sunyer
considered this too preliminary for a Dietary Guideline. Dr. Go
agreed, but suggested that recognition of the issue be made so that
the next DGAC, especially in the post-genomic era, can revisit it. The
Food Forum and IOM conducted a symposium on the topic, and it was
suggested that the Committee contact some of the speakers. Dr.
Caballero noted that some aspects of genetics come into play in
determining an Estimated Adequate Intake (EAR), because a range within
a healthy population is considered, with the variability perhaps
attributed to genetics.
Regarding the risks and benefits of protein, one argument for
increased intake is that there are population groups (such as the
Masai in Africa) who consume an extremely high level of protein and
fat, are lean, and have high levels of physical activity. The
additional protein does not seem to have an adverse effect with regard
to chronic diseases.
Dr. Caballero noted that "three variables" represent "two degrees
of freedom." If the percentage of fats and carbohydrates recommended
are chosen, then the protein level fills in the remainder to reach
100%. That said, the Macronutrient Panel discussed the issue at some
length and did not find compelling evidence to set an upper limit for
protein within the ranges that resulted from their other
recommendations. If protein comes from foods with lower digestibility,
then more must be consumed. For years, protein recommendations were
based on what was called the ideal protein. For many years, the
international standard was based on milk or egg protein, but a
theoretical protein was substituted about 10 years ago. A diet based
on lower-quality protein will require higher nitrogen content. The
Macronutrient Report has some examples, but not enough to be a
Dr. Lupton noted that high levels of obesity and diabetes may make
high protein contra-indicated. She also noted that the Panel reviewed
supplements and felt that upper levels for them were not warranted
based on the available data. However, this may still be an area of
(Break: 11:35 to 1:10)
Energy Balance and Weight Maintenance
Discussion Leaders: X. Pi-Sunyer, R. Pate, and B. Caballero
Dr. Xavier Pi-Sunyer launched this topic with some recent data
about changes in overweight and obesity in the United States and how
they affect disease patterns. The NHANES surveys show that each decade
has seen great increases in numbers of Americans who are overweight or
obese. In 1999, 61% of Americans were overweight or obese. The upward
trend is because of a rise in obesity at a rate of 1% per year, or 10%
per decade. People are moving from the normal to overweight status at
the same rate as those moving from overweight to obese. The problem is
worst for non-Hispanic blacks and for Mexican Americans. Levels are
also rising in children, both sexes and at all age groups. Now,
approximately 11 to 13% of children are overweight, defined as those
with a BMI above the 95th percentile of the earlier NHANES
In the United States, an individual’s weight tends to increase as
one ages, which in other populations, weight remains stable after age
20. As weight increases, so does metabolic syndrome, and this
translates to increased incidence of diabetes. Beginning at a BMI of
25, there is a definite increase in type 2 diabetes. Above a BMI of
35, there is a 40-fold to 90-fold increased risk of developing
Individuals become obese when their energy intake stays the same or
increases while their energy expenditure decreases. The message is
that people should both decrease intake and increase expenditure.
Dietary factors related to intake include macronutrient composition,
energy density, and portion size. Variety and cost are also important.
Dr. Pi-Sunyer queried whether the DGAC wanted to keep or change the
recommended percentages of a weight-reducing diet (carbohydrates 55%
of energy, protein 15%, fats < 30%, of which
£ 15% is MUFA, £
10% is PUFA, and 8 to 10% is saturated fat). One issue is whether the
carbohydrate recommendation might be lower with an increase in
Americans have become more sedentary. Some old data confirm that
below a certain level of activity, the ability to regulate intake is
gone. Regulating mechanisms no longer operate.
He pointed to four failures:
Increased prevalence of overweight and obese Americans
Rise in type 2 diabetes
Rise in metabolic syndrome
Increased degree of disparity by race and ethnicity.
Dr. Russell Pate addressed physical activity and its role in
the Dietary Guidelines and, more generally, in energy balance. The
2000 Dietary Guidelines handled the topic well, and the
recommendations would not be far off even now. However, in the
intervening years, the rise in obesity argues for a re-examination of
the physical activity components of the Dietary Guidelines.
The physical activity community is revising the public health
physical activity guidelines and looking at broad issues related to
disease risk and health promotion. Both the adult guidelines (30
minutes, most days of the week) and children’s guidelines (60 minutes
daily) are under
review, and Dr. Pate was hopeful that the timeline works so that
the DGAC would have their work to review.
The scientific basis for adults’ physical activity guidelines is
much stronger than that for children and youth. But Dr. Pate urged the
DGAC to take advantage of all available resources to develop the 2005
Other new areas in the past five years include the role of
resistance exercise and its impact on resting metabolism and energy
balance. Literature on the benefits of weight-bearing exercise on bone
mass should also be carefully reviewed.
For the 2005 Dietary Guidelines, suggested Dr. Pate, the DGAC
should consider making recommendations about dose (or a range of
doses) for prevention of excessive weight gain, and perhaps for weight
loss and maintenance.
The IOM Macronutrient Panel recommended 60 minutes or more of
physical activity by adults per day. This was somewhat controversial,
but the difference in the two recommendations are not that great.
However he urged clarification so that the public is not confused
about the appropriate dose of physical activity for maintenance of
good health and prevention of weight gain.
Dr. Pate noted that people have asked whether physical activity
would form part of the next Food Guide Pyramid. While he did not know,
he said that the question highlighted the point that the public is
looking at a way to integrate physical activity and diet.
The distinction should be drawn between the prevention of excessive
weight gain and the treatment of obesity. Although important for both,
physical activity has a more profound impact on the former goal than
the latter. However, he also said that more is now known about the
contribution of increased physical activity in maintenance of weight
loss, which may warrant more emphasis in the 2005 Dietary Guidelines.
The impact of television and other screen time on weight has also
become better understood.
There is a limited science base about the advantage of one type of
physical activity over another, with the exception of the role of
weight-bearing exercise in building bone mass. In terms of getting
one’s physical activity in five-minute bouts, Dr. Pate noted that the
1995 Centers for Disease Control and Prevention-American College of
Sports Medicine (CDC-ACSM) recommendations, ratified by NIH consensus
conference and by other organizations, addressed the advantages of
bouts as short as 8 to 10 minutes, but that the literature at the time
did not address shorter bouts. Since then, there have been some
studies that have said even these shorter bouts bring about benefits.
Dr. Benjamin Caballero presented on recent approaches for
determination of dietary energy requirements, with the consideration
of physical activity as a part of the diet. He explained that the IOM
Macronutrient Panel came up with the 60 minutes daily recommendation
through metabolic evidence. The Panel was not charged specifically to
make a recommendation about exercise, but rather more broadly about
energy intake. It became impossible not to consider energy output.
While iron, calcium, and other minerals are an absolute value, energy
is a relative one. A person’s energy expenditure affects how many
calories he or should consume.
For the past 60 years, since the first RDAs were defined, a
factorial method was used. The energy that people expend while resting
was measured, and then an allowance provided for physical activity.
However, there are only imprecise methods of measurement of physical
The Panel used a doubly labeled water database, which is more
precise. It is a composite measurement over several days. Raw data
were requested from investigators worldwide to make a database of
healthy individuals, excluding those who are very physically active as
well as those with a high BMI. It is not a nationally representative
database, he stressed.
Total Energy Expenditure (TEE) goes up until age 30. A person’s
weight and height have an influence on TEE. A measurement for Physical
Activity Level (PAL) was derived as a ratio of the TEE to the resting
energy expenditure. Resting energy expenditure equals a PAL of 1; the
more activity one does, the higher the PAL. Four ranges of PAL were
Sedentary (from 1 to 1.39)
Low active (1.4 to 1.59)
Active (1.6 to 1.89)
Very active (1.9 to 2.5)
A majority of the healthy individuals in the database were in the
active category, indicating that those who have stable weight tend to
be active. A PAL of 1.71 was observed for individuals in the new
dataset, which means that a higher level of physical activity was
assumed than in the previous RDA recommendations published in 1989 (a
PAL of 1.6). Caloric recommendations are different depending on one’s
PAL. The 60-minute recommendation came by compiling a large set of
activities and calculating the impact of each on one’s PAL. By
walking, for example, one’s PAL can be increased by 0.2. The Panel
took the upper end of a sedentary PAL (1.39) and realized that by
walking for an hour, he or she could raise the PAL to the lower range
of active. A workbook was developed that listed activities and how
they can help achieve a PAL of 1.6. This is a metabolic calculation.
Previously, the recommendation was "at least" 30 minutes of
physical activity. The Macronutrient Panel is recommending 60 minutes
daily for a 0.2 increase in PAL to prevent weight gain. The amount of
activity needed to maintain energy balance may be higher than that for
reduction of disease risk.
The 2000 Dietary Guidelines, with their emphasis on aiming for a
healthy weight, are not working—100,000 people per day are passing the
BMI mark of 25. For weight control, some of the recommendations are in
conflict. A person with a BMI of 25 who is sedentary is at higher risk
of disease than a person with a BMI of 27 who is active. An overweight
person who loses weight but stays sedentary has only a limited
reduction in risk. In contrast, in the Diabetes Prevention Program,
physical activity had an effect on diabetes incidence, even in those
with higher BMIs.
Physical activity decreases for children and youth are significant,
especially for teenage girls beginning at age 15, as reported by Kinn
et al in the New England Journal of Medicine.
To prioritize recommendations about energy in the Dietary
Guidelines, Dr. Caballero recommended stating that people should
be more active, even before a recommendation to check their weight.
Physical activity is the most significant determinant of excess weight
in the population.
Dr. Pate considers being more active and checking one’s weight
equally significant. The amount of physical activity that is necessary
to prevent weight gain is highly individual. Thus, a blanket
recommendation about the amount needed to prevent weight gain is not
supported in the literature and would not be helpful. Some people need
less than 30 minutes to maintain weight; some need more. Monitoring
one’s weight lets a person know his or her needs. He applauded the IOM
Panel’s effort as a major step forward, as well as the effort to pull
together the doubly labeled water data, even though they are
cross-sectional data. Long-term prospective studies are needed.
The amount of caloric imbalance that starts to create weight gain
is difficult to measure, but can be 100 to 200 calories a day. Most
people gain weight slowly over time. Dr. Pate expressed more optimism
about the chances of prevention of weight gain than the treatment of
those already overweight or obese.
Most calculations are based on an average amount per day. However,
as Dr. Caballero noted, if one goes to a party, for example, more
calories might be consumed that particular day. The problem is an
environment hostile to counterbalancing the calorie excesses of a
given day. Another practical issue is that people have trouble
distinguishing between, for example, a 400-calorie sandwich and an
800-calorie sandwich. A radical proposal would be that all packaged
foods list their caloric content. Another would be to try to teach
Americans how many calories they should consume daily at their current
PAL level. Americans also need to know the caloric content of
different types of physical activity. A walk around the block does not
mean that one will then burn off a hot fudge sundae.
Dr. Pate cautioned about directly linking the caloric content of
different foods with the calories expended in different exercise
modes. It can sound too defeating—i.e., that the way to burn off 800
calories is to walk for eight miles. In dealing with weight
prevention, it may not be the 800 calories that a person has to deal
with, but perhaps 100 extra calories.
The discussion then turned to the macronutrient composition of the
diet and physical activity on prevention of weight gain or on weight
loss, and whether the DGAC should address various diet plans. Dr. Pi-Sunyer
responded that the target of the DGAC should perhaps be to prevent
weight gain, as opposed to weight loss strategies. He did discuss some
of the popular diet plans. They recommend different percentage amounts
of protein, fat, and carbohydrates. When tested in a metabolic ward,
it is the total calories that have an impact, not their composition,
on weight loss. The question then becomes whether certain diets will
change the satiety ratio and inhibit further eating. Is one diet more
effective than another over the long term? This is where macronutrient
composition plays a role. This is an important issue, but complicated
and a matter of individual preference. The message should probably be
that a person could probably lose weight and maybe prevent weight gain
with various macronutrient combinations. At this time, there are no
long-term data on the effects of a high protein-high fat diet on
The Dietary Guidelines should not be cast as a strategy to lose
weight. Prevention of weight gain is the goal, especially in children.
Even for those who are already overweight, the prevention of more
weight gain is important. Weight cycling is not healthy. Across the
board we should be saying—do not gain more weight. Along those lines,
Dr. Kris-Etherton suggested looking at the evidence and stating the
benefits of even losing 10 pounds. Also, she stressed the importance
of the message that "a calorie is a calorie," no matter whether from
fat, carbohydrate, or protein.
Dr. Bronner stated that the fact that weight gain is slow and
progressive should be underscored—a lot of people do not realize how
much weight they have gained over time. There are studies that people
are more aware when they weigh themselves regularly. The data about
weight maintenance suggest that people should weigh themselves at
least once a week. If people become aware of a weight gain, they can
make immediate adjustments.
Dr. Caballero noted, although the dataset created for the IOM
report only included healthy weight individuals, there was additional
data from overweight individuals that was analyzed separately. It was
found that the estimates of the energy needs of overweight versus
normal weight people were almost the same. If we can help people avoid
weight gain, we can stop this move from normal to overweight, and from
overweight to obese. He reiterated the need to focus energies on those
in the healthy BMI range in order to create simple, direct messages.
In the 2000 Dietary Guidelines report, weight loss is dealt with in a
vague way. It is not too useful for those embarking on a weight loss
In response to a question about how well BMI correlates with body
fat, Dr. Caballero said that it varies from population to population.
Generally, it is not a bad indication, but can be misleading. For this
reason, many surveys now include body fat as a separate measure. It is
unlikely that, through looking at one’s BMI, he or she would be
misclassified as obese. There might be a few cases of someone who has
a high BMI but is very athletic, such as a football player. However,
it does not seem an issue with the general population.
Just saying eat less/exercise more is not sufficient. Dr. Camargo
suggested that educating people about calories is important. In
addition, perhaps more is needed—such as recommending that exercise
facilities be made available and that physical education remains in
the schools. Dr. Pate noted that the previous Dietary Guidelines
couched the recommendations to individuals. Perhaps there need to be
companion recommendations to institutions, policy makers, and others.
In exercise science, people are exploring this and moving beyond
public health education. This might apply to other recommendations.
For example, Dr. Appel suggested that there might be a guideline for
individuals about sodium, but also to governments and manufacturers.
There may be ways to suggest incentives: for example, tax breaks to
companies that give employees time to exercise. Some of the
recommended solutions are system-wide. Until they are in place, the
trajectory toward excess weight will continue.
Returning to the topic of body fat and BMI, women at every BMI
level tend to have more body fat than men. BMI has an independent
correlation for risk of disease and mortality. Another possibility of
self-assessment is through waist circumference, using cutoffs such as
belt sizes of 35 inches for women and 40 inches for men.
Regarding the 2000 Dietary Guidelines’ different recommendations
for physical activity for adults and children, Dr. Pate reiterated
that the scientific basis is firmer for adults. The consensus
recommendation of 60 minutes daily for children was derived through a
bit of a "back door approach." It seemed to be ahead of what most
children do, but still attainable.
Weight loss in the elderly is somewhat controversial. Once people
reach 65, some say not to intervene. However in the Diabetes
Prevention Program (DPP), the elderly did well. In terms of morbidity,
the DPP indicates that the elderly would benefit, although the
mortality data are not as clear. The elderly do well when looking at
blood pressure control. There is also an orthopedic issue—we want to
prevent weight gain so that older people are able to get around.
Decision about Whether to Proceed with Revised 2005
In reflecting on the presentations over the past two days, Dr. King
asked the DGAC whether members felt further evaluation of the science
was necessary. In other words, are the 2000 Dietary Guidelines based
on science that has not changed?
Dr. Camargo made a motion to continue to evaluate the data from the
last five years and make new recommendations. Dr. Go seconded the
motion. It was amended by Dr. Appel to include a focus on the last
five years, but being able to go further back if necessary. The
amendment was agreed to by consensus, and the motion passed
(Break: 2:40 to 2:50)
Systematic Approach to the Science Review
Discussion Leaders: J. Lupton and L. Appel
Dr. King introduced this session by noting that a systematic
approach to science reduces bias, maintains objectivity, and improves
reliability. It also makes the process more transparent. Finally, a
systematic approach means that future Committees will have this work
as a foundation.
Dr. Joanne Lupton first presented on "Evidence-based Systems
Application to the Dietary Guidelines Process." She divided her
presentation into four parts:
Description of evidence-based rating systems
Their importance and use
How they work
Adaptation of existing systems to the needs of the DGAC
An evidence-based rating system is a science-based systematic
evaluation of the strength of the evidence behind a recommendation,
such as how to treat a patient, what diet to recommend, or, in this
case, how to modify or adopt a dietary guideline. They are used to
make important decisions based on a review of current science, but
value judgments are also necessary. There will never be a perfect
amount of information—recommendations must be made all the time with
imperfect data. There are many evidence-based rating systems. The
Agency for Healthcare Research and Quality (AHRQ) evaluated many of
those currently in use in 2002.
An evidence-based rating system works through this process:
Define the question/statement
Collect all relevant studies
Evaluate each study independently for its type and quality
Rate the strength of the body of evidence
Report the strength of the science and make a recommendation
(which is what the DGAC must do).
For example, if it was proposed to add trans fat to the
current Guideline that states that people should choose a diet low in
saturated fat and cholesterol, then the Committee would have to choose
a testable statement and review the data to see if the evidence were
as strong for trans fat as for saturated fat and cholesterol.
Issues involved would be whether to revisit studies or rely on such
authoritative statements as the IOM report at face value. The
Committee would also have to decide whether to use only studies
conducted since the last authoritative statement and whether to limit
the types of studies used (e.g., exclude animal or in vitro studies,
or studies not in English). Once the Committee makes these decisions,
the staff could do a literature search.
Data are extracted from the studies and put in tabular form, after
the Committee has decided which data should be extracted. Staff, if
possible, would do the data extraction for the Committee’s evaluation.
Studies would be rated based on their type, from a randomized
controlled clinical trial (an "A") to a cross-sectional study (a "D").
The quality would be based on agreed-upon criteria, and each study’s
evidence assigned a +, -, neutral, or N/A. AHRQ has identified various
generic systems to rate study quality. AHRQ has also identified seven
systems that fully address quality, quantity, and consistency in
rating the strength of the evidence. Grades could be assigned from
Good (strong design, clinically important and consistent, adequate
statistical power), to Fair, to Limited.
The end product would be a statement on diet and health with a
rating of the scientific evidence behind the statement. It would be a
clear and transparent demonstration of which research studies were
evaluated to provide the rating, with evidence tables that show the
rigor of the evaluation.
Dr. Lawrence Appel presented "A Systematic Approach to
Scientific Review" and noted that there would be some overlap with Dr.
Rating schemes, he said, work well with medical therapies but
sometimes there is imperfect evidence associated with prevention.
Although the "gold standard" of studies is experimental, the fact is
that studies are often done for different reasons and, thus, are
designed differently. For example, a randomized, controlled trial may
not be the best way to estimate prevalence since there are very few
randomized trials that actually sample a population. The U.S.
Preventive Services Task Force presented a hierarchy of evidence, from
expert opinion as the weakest to a randomized trial as the strongest
(meta-analyses were not included). In the IOM Evolving Science
Committee related to dietary supplements, a hierarchy of evidence was
also created. The NIH Consensus Statements assign a "D" to consensus
of opinion up to an "A" for substantial number of well-designed
trials. However, in looking at the studies that exist for the Dietary
Guidelines, there might not be a lot of A’s, or even B’s. Much of the
literature will be trials with surrogate outcomes and observational
Dr. Appel noted that the most acceptable outcome variable for
decision making is total mortality. Everything below that would be
considered a surrogate outcome; the Committee would have to decide
which surrogate outcomes it will accept. It depends on how rigorous a
basis is desired. There are relatively few trials with clinical
outcomes as compared to observational studies and trials with
surrogate outcomes. For example, we know that reduced weight leads to
lowered blood pressure, and that lower blood pressure leads to fewer
coronary heart disease events. However, there are not studies that
link weight directly with CHD.
Other issues for the DGAC to consider:
Should we do independent literature searches or augment the DRI
Should we compile evidence tables or just refer to selected
tables in the DRI reports or other reviews?
Should we conduct literature searches on topics not well covered
in the DRI reports, such as dietary patterns?
Dr. King thanked the presenters and referred DGAC members to Tab 7
of their notebooks, which contained a suggested approach to the review
of evidence. She noted that an organized literature review would lead
to more confidence in the recommendations, but that there are limited
time and resources available. Thus, the question comes down to what
would be the most meaningful activity.
Dr. Lupton suggested that the DGAC define the questions it wants
answered very clearly. The subcommittees could make suggestions to
take to the full committee. Philosophical decisions on how far back to
go in a literature search are important, so that time is not wasted
searching for studies that will not be used. Dr. Pi-Sunyer suggested
looking up previous evidence-based reports, such as the DRI, and then
bridging the gap between when those end and the present. Most topics
have been addressed by some group (e.g., DRI, NIH, professional
societies), noted Dr. Appel, and the DGAC’s role is to make sure that
there is evidence to cite and that additional evidence is updated as
needed. There will be more questions on some issues than others. It
was agreed that the DGAC could use the evidence tables of other groups
without necessarily relying on their conclusions.
Dr. King summed up that the DGAC would divide into Subcommittees.
Each Subcommittee would bring one or two clear proposed changes or
questions to the next meeting for which they think the DGAC would need
an evidence-based search. The challenge for each Subcommittee is to
predict the most important issues. The search would start with already
conducted systematic reviews, and then address the literature since
that review was written (as opposed to published). The third step
would be for staff to collect the literature and summarize it in a
Dr. King directed the DGAC members to Tab 7 for a potential
template to summarize the literature and asked for comments. The
template includes columns for—
Study design methods
Weakness or strength of evidence
Sponsor of the work
It was suggested that columns for sample size and duration of the
intervention be added, and that study method needs to be well defined.
Dr. King asked Dr. Lupton and Dr. Appel to work with staff to modify
the template. In terms of training to rate the evidence, Dr. Lupton
said that extracting the information should not be that difficult.
The role of public comment to the DGAC was then addressed. Dr.
Hentges felt it necessary to consult counsel to ensure that the
correct procedures are followed for notifying the public of the
opportunity. After some discussion it was agreed that, if feasible,
public testimony would be scheduled for the next DGAC meeting. The
January meeting would also provide time for discussion about how to
evaluate the body of evidence as a group and each Subcommittee would
present several questions. Staff in the meantime would begin to do
literature and systematic reviews. Dr. Appel noted that the hierarchy
of evidence relates to clinical models and that looking at prevention
might mean having evidence ranked from a ‘B" or "C" study in terms of
design (e.g., not a randomized trial).
It was discussed how to deal with each Subcommittee’s issues beyond
the one or two major questions to present to the whole Committee. Some
prioritization is necessary, with perhaps a look at previous research.
If there seems to be information needed that is not in the literature
that staff might be able to provide, this needs to be identified soon.
If there are more issues than the staff can address, then other
processes may need to be used, such as the DGAC members carrying out
their own searches.
Dr. King proposed organizing the Subcommittees around the same
topics as the presentations of the past two days. She divided the DGAC
- Nutrient Adequacy and Life Cycle Needs: C. Weaver, lead; Y.
Bronner, V.L.W. Go, T. Nicklas
- Food Safety: F. Clydesdale, lead; C. Camargo, C. Weaver
- Fluid and Electrolytes: L. Appel, lead; B. Caballero, R. Pate,
- Ethanol: C. Camargo, lead; L. Appel, P. Kris-Etherton
- Carbohydrates: J. Lupton, lead; F. Clydesdale, R. Pate, X. Pi-Sunyer
- Fatty Acids: P. Kris-Etherton, lead; C. Camargo, V.L.W. Go, T.
- Energy Balance and Weight Maintenance: X. Pi-Sunyer, lead; L.
Appel, B. Caballero, R. Pate
- Dr. Bronner will also work on crosscutting issues specific to
the life cycle.
Subcommittees should also identify individuals who might provide
expert presentations at the January meeting, which might take
two-thirds or up to a full day. Several hours would be set aside for
public comment. There will be a discussion on how to review the bodies
of evidence and each Subcommittee would report back to the entire DGAC
on questions to be answered and their priority. The staff, in the
meantime, would begin the literature searches.
After some discussion about the location of the next meeting,
Washington, D.C. was decided upon to facilitate participation by the
public and by government staff.
Dr. Hentges thanked the DGAC on behalf of Dr. Beato and Mr. Bost.
The Co-Executive Secretaries expressed that they were looking forward
to working with the DGAC on the Dietary Guidelines and invited the
members to contact them for any background reports needed. In the
meantime, they will forward relevant reports and public comment to all
Dr. King thanked the Committee members for their work and adjourned
2005 Guidelines Page