Here's What Happens When You Go Vegan for a Month

When Aleksandra Shai Chai learned she'd have to follow a vegan diet for eight weeks as part of a Stanford University health study, she wasn't happy. But as the Washington Post reports, giving up her beloved steak, bacon, and sushi came with advantages. Researchers assigned one half of 22 sets of identical twins a healthy plant-based diet, while their siblings were assigned a healthy diet of meat and vegetables. After eight weeks, the vegan group was found to have lost more weight, with greater reductions in insulin levels and low-density lipoprotein, also known as "bad cholesterol."

The study used twins as a means of controlling differences in genetics and environmental factors among study participants that can affect health, thereby offering "a groundbreaking way to assert that a vegan diet is healthier than the conventional omnivore diet," says Christopher Gardner, a Stanford professor of medicine and lead author of the study published Nov. 30 in JAMA Network Open. The variations observed weren't minor. Vegan participants reduced their LDL by 15.2 milligrams on average, compared to 2.4 milligrams for the omnivore group. Insulin levels fell by 20% more than with the other group, and vegans lost 4.2 more pounds on average, per ABC News.

"Anyone who chooses a vegan diet can improve their long-term health in two months, with the most change seen in the first month," says Gardner, who notes a vegan diet can reduce saturated fat and increase gut bacteria. He stresses the diet "is accessible to anyone, because 21 out of the 22 vegans followed through with the diet." Shai Chai—who received prepackaged meals during the first half of the study before preparing her own vegan dishes—didn't always enjoy her meals of tofu, beans, lentils, and broccoli, but felt she had more energy and slept better, she tells the Post. Though the 43-year-old returned to her usual diet, she says the results "made it all worth it." (More vegan diet stories.)