Walter C. Willett, M.D., Dr P.H., is Professor of Epidemiology and Nutrition at Harvard T.H. Chan School of Public Health and Professor of Medicine at Harvard Medical School.

Dr Willett advocates for a sensible and careful approach to consuming supplements. Dr Willett is the most cited nutritionist internationally, he has published over 1,700 original research papers and written the textbook, Nutritional Epidemiology. He is also the author of four books for the general public, the best known being Eat, Drink, and Be Healthy: The Harvard Medical School Guide to Healthy Eating.