I need help in Ballet?

I have started ballet for 5 years. Now I'm 17. And I'm worrried to realize that my legs (and my classmates') are getting bigger. I don't know why. I dance every night from 6 - 9PM. After that I just eat fruit for my dinner. Or maybe I danced in a wrong way??? Whenever teachers in my school teach new moves, they say we should feel it if it's right or wrong. We followed their advices. We feel normal. But our legs are bigger? Can anybody tell me why?

And can you tell me what kind of food should I use??

I need help in Ballet?musicals

maybe you're building new muscles =)

and don't starve yourself, that makes things worse.

I need help in Ballet?opera songs opera theater

I prefer painting, writing, shopping and cooking. I enjoy walks, biking, hikes, swimming, bowling, Badminton, volleyball, baseball, horses, etc. the Internet, working, movies, reading, television, etc. Don't ask me about dancing. I do not know.
you're just probably building muscles. after class, make sure to stretch and cool down or try massaging the areas that were usually used.
Well your legs just might be getting stronger and eat a lot of vegetables
I was a dancer for 16 years, and I built up pretty large calves and quad muscles (for a girl). If they're becoming too large, especially your calves, you might want to pay attention to how you're landing from jumps. If your heels pop up, even a tiny bit when you land, that might be the culprit. It certainly was for me. It's been about 8 years since I stopped, and my quads aren't as big as they used to be, but my calves are still pretty developed.
You are building mucle. Keep eating. But as you are in ballet and I have been dancing ballet my whole life you are not using your turn out muscles. You are building the wrong kind for ballet. Ask your teacher after class one day what muscles in your leg you should be using. I hope eveything works out. Don't get discouraged and keep dancing!
You need to stretch out more...if your legs are getting bigger than your building to much muscle. A dancer should be long and lean... no bunchy muscles. I'm guessing your teacher needs to add some more streching into your warm-up.
Is it muscle? ya never know and try to do it ups and other excersizes i have this video and its SOOOO cool it will hurt but u get a AMAZING results its called The New York City Ballet Workout
I thought Morgan gave a good answer.

I would add this:

It's natural for you to gain muscle mass if you're dancing a lot.

It may be due to your genetics.

I also disagree with your teacher. Dancers often don't feel/know that they're doing something incorrectly. You need a great teacher to guide you with good technique. What is your teacher's training? Make sure your teacher has a BFA in dance or a certification in Cechetti or another technique.