In order to carry out the policy of this subchapter, the Secretary shall develop and implement a national food and human nutrition research and extension program that shall include, but not be limited to—

(1) research on human nutritional requirements;

(2) research on the nutrient composition of foods and the effects of agricultural practices, handling, food processing, and cooking on the nutrients they contain;

(3) surveillance of the nutritional benefits provided to participants in the food programs administered by the Department of Agriculture;

(4) research on the factors affecting food preference and habits; and

(5) the development of techniques and equipment to assist consumers in the home or in institutions in selecting food that supplies a nutritionally adequate diet.