David Mark Hegsted (March 25, 1914 – June 16, 2009) was an American nutritionist who studied the connections between food consumption and heart disease.

His work included studies that showed that consumption of saturated fats led to increases in cholesterol, leading to the development of dietary guidelines intended to help Americans achieve better health through improved food choices.

He came to the Department of Nutrition at the Harvard School of Public Health in 1942 after spending a year at Abbott Laboratories as a research chemist.

[2] Research performed by Hegsted in the early 1960s studied the relationships between changes in diet and serum levels of cholesterol.

Results from these studies were published in 1965 in the American Journal of Clinical Nutrition,[3] to what was described by The New York Times as "great acclaim".

In combination with research performed independently by Ancel Keys, these results led to recommendations advocating decreased dietary consumption of saturated fats.

[4] In 1978, he was hired by the United States Department of Agriculture as Administrator of the Food and Nutrition Service, serving until 1982.