“In a Harvard University study, the diets of nearly 1,000 women were analysed before their morning melatonin levels were measured. Meat consumption was the only food significantly associated with lower melatonin production, for reasons that are as yet unknown.”

American physician, author, and public health speaker

Michael Herschel Greger is an American physician, author, and public health speaker known for his advocacy of a whole-food, plant-based diet and his criticism of animal-derived food products. He has built a large audience around nutrition, health, and preventive medicine. He founded NutritionFacts.org, a site that shares videos and research on diet and nutrition. He is also the author of How Not to Die, How Not to Diet, and How Not to Age, all of which became New York Times best sellers.