Every infant or child has a genetic potential for physical, mental,
and emotional growth. Providing nutrition that fulfills all aspects
of that growth potential represents optimal nutrition.
When nutrition either limits growth or results in excessive body
mass, because of either inadequate quality or inappropriate quantity, an
individual is suffering from malnutrition (ie, undernutrition or
All published dietary requirements are guidelines designed to
assure that most individuals will be well nourished. They are not meant
to be rigidly followed by any specific individual. Precise adherence
to these guidelines by any one person does not guarantee that an
individual will be well nourished.
In 1988, the first Surgeon General’s Report on
Nutrition and Health concluded that overconsumption of
certain dietary components now is a major concern for Americans.1 The disproportionate
consumption of foods that are high in fats, often at the expense
of foods that are high in complex carbohydrates and fiber (eg, vegetables,
fruits, and whole-grain products), increased the risk of diet-related diseases.
The report reiterated the dietary guidelines issued jointly by the
US Department of Agriculture (USDA) and the US Department of Health
and Human Services. The recommendations of the Dietary Guidelines for
Americans, as revised in 2005, are summarized here2:
- Eat a variety of nutrient-dense foods and beverages.
- Balance the food that you eat with regular physical activity.
- Choose a diet with plenty of grain products, vegetables, and
- Choose a diet low in fat, saturated fats, trans fats,
- Choose a diet moderate in sugars and salt.
The USDA has defined a system of 5 basic food groups that, when
combined appropriately, should provide the average American with his
or her nutritional needs. These 5 groups are vegetables, fruits,
grains (eg, breads, cereals, pastas), dairy products, and proteins
(eg, meat, poultry, fish eggs, nuts, legumes). Fats, oils, and sweets
are separated, and it is recommended that they be “used
The Food and Nutrition Board (FNB) of the Institute of Medicine,
National Academy of Science, has collaborated since 1992 to revise
the recommended dietary allowances (RDAs).3 Following
an explosion of nutrition-related scientific data, the FNB decided
to replace the recommended dietary allowances with dietary
reference intakes (DRIs), which broadened the focus of
the FNB as well as guidelines for the United States and Canada.
The dietary reference intakes were established to meet a variety of
uses, those focused on the intake and adequacy of populations as
well as individuals. The FNB investigated the connection between
nutrient intake and the risk reduction for chronic disease. In addition,
upper limits for nutrients were established, specifically addressing
therapeutics and toxicities. The following are four categories that comprise
the general heading of dietary reference intakes:
- Estimated average requirement (EAR). An
estimated nutrient intake value that meets the requirement of half
the healthy individuals in a group or population according to accepted
scientific research. ...