Find information on medical topics, symptoms, drugs, procedures, news and more, written in everyday language.

* This is the Consumer Version. *

Nutritional Requirements

by Adrienne Youdim, MD

General guidelines for a healthy diet have been developed even though daily nutritional requirements, including those for essential nutrients, vary depending on age, sex, height, weight, physical activity, and the rate at which the body burns calories (metabolic rate). Recommended dietary allowances for protein, vitamins (see Table: Vitamins), and minerals (see Table: Minerals) are periodically published by The Food and Nutrition Board of the National Academy of Sciences–National Research Council and the U.S. Department of Agriculture. These allowances are intended to meet the needs of healthy people.

The U.S. Department of Agriculture also provides an interactive tool called Supertracker at My Plate . This tool enables people to enter information about themselves (their age, sex, activity level, and foods usually eaten) so that they can evaluate their diet and get recommendations about healthful foods and portion sizes that can help them reach and maintain a healthy weight. The amount of food needed each day from each food group varies depending on the person’s energy needs.

In general, authorities recommend that

  • People reduce fat intake to about 30% of calories or less.

  • Most of the fat eaten should be polyunsaturated or monounsaturated fats.

  • People reduce the amount of saturated fats they consume.

  • People should eliminate trans fats from their diet.

  • People should consume more fruits, vegetables, and cereals (most Americans eat do not eat enough).

  • People should drink enough fluids to prevent thirst. However, as people age, their ability to sense thirst decreases, so they may need to make a conscious effort to drink enough fluids.