Mary Gertrude Enig, PhD, was a nutritionist and researcher known for her unconventional positions on the role saturated fats play in diet and health. She was an early researcher of trans fatty acids, warning of their dangers before this perspective was widely accepted. She advocated for a diet based on whole foods and rich in certain saturated fats and believed both butter and coconut oil are good for heart health.

Along with Sally Fallon, Enig co-founded the Weston A. Price Foundation (WAPF) in 1999. 

Enig and Fallon co-wrote the book Eat Fat, Lose Fat which promotes what Enig considered "good" fats, including fat from coconut, butter, cream, nuts, meat, lard, goose fat, and eggs. In the book, Enig argued that many who follow low-fat diets feel low on energy because they are "fat deficient."

Enig died of a stroke in 2014 at the age of 83.