A guide to serve as a goal for good nutrition and as a yardstick by which to measure progress toward that goal has long been needed. The Committee on Food and Nutrition of the National Research Council was established in 1940 to advise on nutrition problems in connection with national defense. One of its first concerns was to work out recommended daily allowances for the various dietary essentials, for people of different ages. Recommended Dietary Allowances develops a table of allowances that represents the best available evidence on the amounts of the various nutritive essentials desirable to include in practical diets. These values represent the combined judgment of nutrition authorities in various parts of the country. This information serves as a guide for planning adequate nutrition for the civilian population of the United States.