the guidelines will continue to change to reflect new
insights into diet and health. People can take steps
toward healthier lifestyles by following the recommen-
dations of the Dietary Guidelines and using tools like
the Food Guide Pyramid to guide their food choices.The 2000 Dietary Guidelines for Americans
Aim for Fitness
Aim for a healthy weight
Be physically active each day
Build a Healthy Base
Let the Pyramid guide your food choices
Choose a variety of grains daily, especially whole
grains
Choose a variety of fruits and vegetables daily
Keep food safe to eat
Choose Sensibly
Choose a diet that is low in fat and cholesterol and
moderate in fat
Choose beverages and foods to moderate your intake
of sugar
Choose and prepare foods with less salt
If you drink alcoholic beverages, do so in moderationResources
BOOKS
National Research Council (1989).Diet and Health: Impli-
cations for Reducing Chronic Disease Risk. Washington,
DC: National Academy Press.
U.S. Department of Agriculture, and U.S. Department of
Health and Human Services (1980).Nutrition and Your
Health: Dietary Guidelines for Americans. (Home and
Garden Bulletin 232.) Washington, DC: U.S. Govern-
ment Printing Office.
U.S. Department of Agriculture, and U.S. Department of
Health and Human Services (2000).Nutrition and Your
Health: Dietary Guidelines for Americans, 5th ed.
Washington, DC: Government Printing Office.
U.S. Department of Health and Human Services, Public
Health Service (1988).The Surgeon General’s Report on
Nutrition and Health. (DHHS ‘PHS’ Publication No.
88-50210.) Washington, DC: U.S. Government Print-
ing Office.
PERIODICALS
Cronin, Frances J., and Shaw, Anne M. (1988). ‘‘Summary
of Dietary Recommendations for Healthy Americans.’’
Nutrition Today23:26–34.Linda Benjamin BobroffDietary practiceseeReligion and dietary
practiceDietary reference intakes
Definition
Dietary reference intakes (DRI) are a set of refer-
ence values forvitamins,minerals, and other nutrients
important to human health. DRIs provide guidance
about the appropriate amount of each nutrient that
should be consumed based on American and Cana-
dian diets. DRIs are specific to age group, gender, and
for women, reproductive status.Purpose
DRIs are tools intended to be used in planning
and assessing diets of individuals and groups. They are
based on data that applies to American and Canadian
populations and replace previously issued Recom-
mended Dietary Allowances (RDAs) in the United
States and Recommended Nutrient Intakes (RNIs)
in Canada.Description
Health is strongly affected by the food that people
eat, and proper diet can delay, prevent, or treat certain
diseases and disorders. Research on dietary vitamins
and minerals in the 1920s and 1930s led to the publi-
cation of the first RDAs in 1941 by the Food and
Nutrition Board of the National Academy of Sciences.
These early RDAs were based on the amount of each
vitamin or mineral that was needed to prevent symp-
toms of the corresponding nutrient-deficiency disease.
For example, the RDA forvitamin Awas set at a level
that would prevent symptoms of night blindness. The
availability of RDAs gave a boost to food fortification
programs that helped eliminate many vitamin defi-
ciency disorders such as pellagra, which is caused by
niacindeficiency.
The RDAs were reviewed about every five years
and the values were adjusted as additional research
became available, but for many years the underlying
assumption remained one of setting dietary intake
level of each nutrient to prevent disease. Multi-vitamin
dietary supplementshave been in use for many years.
By the early 1980s single-ingredient dietary supple-
ments, many claiming to boost athletic or sexual per-
formance, increase energy, prevent disease, or control
weight, had become much more common. Research
on these dietary supplements showed that some vita-
mins and minerals taken in quantities larger than the
RDA appeared to provide benefits to healthy individ-
uals, but the same supplement taken in too large a
quantity could be harmful. The Institute of MedicineDietary reference intakes