My friend keeps making judgements about my weight?

I'm not fat, nor was I ever fat, just a little chubby. I'm 5'3", 16 years old, and weighed 145 pounds a couple of months ago. I wasn't fat, but i DID want to start eating healthier and slim down a little. I started counting calories with the LoseIt! app on my iPod and I lost 30 pounds in a month and my friend was really excited that I lost weight that quickly so she decided to jump on to the weight loss train. She was never actually big to begin with, she weighed 108 and wanted to bring it down to 100. Since we started losing weight, she always has to make comments to me. For example, if we go out to eat and I want to pick something from the menu, she'll say "Do you know how many calories are in that? Are you sure you can eat that today?" She worries about my calories in a condescending way like I don't know what I can and can't eat! I'm better about my calories than she is and I always pre-plan my meals for the day just to make sure it fits in my calorie budget, so for her to treat me like an idiot, it ticks me off. Another thing, since it's summer, we usually go out to swim in her pool or to the beach, and everytime she sees me in a bikini, she'll tap my stomach and say "OOooh! someone's chunky!" I laugh along with her, but it really bugs me. Even if i'm not in a bikini, like, if i'm just wearing shorts and a t-shirt, she'll say something about my jiggly thighs or my chicken wing arms. I'll try to make a comeback like, you have jiggly thighs too, but she'll just say "well it's not as bad as yours!". I hate being around her now because she annoys me with her comments. How can I deal with this? or better yet, how can I make her stop?