He was responsible for initiating nutrition research in independent India, leading to a number of interventions such as the Integrated Child Development Services, the midday meal scheme for school children, goiter prevention programme, etc.

Gopalan's research led to a midday meal scheme for school children and a goiter prevention programme.

[8] He set up divisions for clinical research, biochemistry, bio-physics, endocrinology, analytical chemistry, food toxicology and the field units in multi-disciplinary subjects.

National Nutrition Monitoring Bureau which is product of his effort started the research to tackle problems such as protein energy malnutrition, Vitamin A deficiency, Phrynoderma, Lathyrism, fluorosis and Pellagra.

He analysed over 500 Indian foods for their nutritive values and published a detailed study report of that.