Thomas Colin Campbell (born March 14, 1934)[1] is an American biochemist who specializes in the effect of nutrition on long-term health.

[12][13] Campbell grew up on a dairy farm and studied pre-veterinary medicine at Pennsylvania State University, where he obtained his B.S.

[16][17][18] He was also a student of Clive McCay, a pioneer in modern biogerontology, known for successfully extending the lifespan of mice through reduced caloric intake and advancing calorie restriction research.

[20] He has worked as a senior science adviser to the American Institute for Cancer Research,[16][21] and sits on the advisory board of the Physicians Committee for Responsible Medicine.

[22] He is known in particular for research, derived in part from the China study, that appears to link the consumption of animal protein with the development of cancer and heart disease.

[2][23][24] Specifically, preliminary results from a large study involving 6,500 people in China showed a reduced risk of cancer, heart disease, diabetes, osteoporosis, and other illnesses among those who followed a plant-based diet.

[29] Campbell's book, The China Study, was influential in persuading President Bill Clinton to adopt a vegan diet to lose weight and improve his heart disease.