Do your friends determine how you see yourself?

I have a friend who is very beautiful physically, is an incredible dancer, very intelligent, and always knows the right thing to say in a situation. The most prominant thing, though, is her ability to eat whatever she wants and still stay slim. Now i am the same way to a certain point. People consider me pretty, I am on the honour roll, and I make friends very easily. The thing is, I have a very hard time with my weight. I am not overweight. On the contrary, I am quite slim. But it takes alot of work for me to stay that way. Now it has never occurred to me to be bothered by it before, I barely noticed it. But ever since I met my friend, I have felt worse and worse about my weight, and moreso since I gained 10 lbs. I am wondering if maybe I should discontinue being friends with her since I only started feeling bad about myself since meeting her?

What good does it do to have a perfect friend, if you feel bad when you see her? Spend time with people who makes you feel happy and good about yourself.