Bill Clinton became a vegan

"I'm trying to be one of those experimenters," said Clinton. "Since 1986, several hundred people who have tried essentially a plant-based diet, not ingesting any cholesterol from any source, has seen their bodies start to heal themselves — break up the arterial blockage, break up the calcium deposits around the heart. 82 percent of the people who have done this have had this result, so I want to see if I can be one of them."

Clinton decided to adopt the diet in the early part of May 2010. While he does occasionally eat fish, the former president otherwise follows a strict vegan diet.
What made him go vegan? Clinton has read many books on the topic, including books by T. Colin Campbell, Caldwell Esselstyn and Dr. Dean Ornish. Although losing weight was a benefit of the dietary change, the choice to go vegan was about more than just losing weight.
With time, Clinton could become the most outspoken proponent of a complete vegan diet."