There's nothing wrong with wanting to look like your thin friend, but the problem is, when you go out to eat together, you copy her eating habits. In a way you think, "If she can eat an entire plate of pasta and not gain an ounce, then why can't I?" But you're not her, and you don't share her metabolism or her workout schedule. Don't worry, you're not the only one emulating your thin friends' eating habits. Studies show that when people's thin dinner companions ate more, they ate more too. The next time you're out to dinner with a slim buddy, be conscious about eating an appropriate amount of food for you, and don't try to mirror your friend.