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.