Few would have guessed it, considering the diet he kept on the campaign trail over the years, but former president Bill Clinton has gone vegan. Clinton told CNN's Sanjay Gupta that he gave up eating animal products in order to reduce his risk of heart disease. After his bypass surgery last year, Clinton says, "I essentially concluded that I had played Russian roulette.” He's also lost 20 pounds. Studies show that people on a vegan diet—which bans milk, cheese, and eggs in addition to meat—lose weight and have lower cholesterol and better glucose control. However, they can also be short on vitamin B12, iron, protein, zinc, and calcium.