Answered by: Dr. Michael Greger
Fabulous question! There was a study involving four thousand participants that compared traditional Asian diets with and without occasional servings of meat. The researchers found that men who avoided meat altogether had only half the odds of diabetes compared to those eating a serving of meat every few days, and the vegetarian women had 75% lower odds of diabetes than women who were otherwise vegetarian but averaged a single serving of meat a week. We don’t know exactly where that dividing line is, but we do know based on the Adventist data that vegetarians who start to eat meat at least once a week appear to experience large increases in the risk of heart disease, stroke, diabetes, and weight gain. During the twelve years after the transition from vegetarian to omnivore, meat-eating was associated with a 3.6 year decrease in life expectancy.
From a nutrition standpoint, I’d much rather see people eat, for example, the traditional Okinawan diet which is largely (but not exclusively) plant-based, than the strictest 100% vegan diet centered around french fries and vegan Doritos. Unprocessed plant foods are the healthiest options, so the more we can squeeze into our daily diet the better. Health-wise it doesn’t really matter what we eat on holidays or special occasions; it’s our week-to-week choices that makes the most difference for our long-term health and longevity.