Will Being a Vegan Make You Thin?

Alicia Silverstone credits her Vegan lifestyle as the cause for her massive weight loss post Batgirl. She claims she no longer has to worry about her weight since she cut out meat and dairy products. Silverstone became a vegetarian in 1999 once she became aware of the violent way pigs in farms were treated.

Conversely, Drew Barrymore announces that the reason she has been able to keep off the 20 lbs. she lost in 2004 is because she gave up her vegetarian diet. She claimed her meat-free diet was a giant carbfest.

So, which is it? Does meat make you gain or lose weight?