I had the same problem when I cheered. Don't let anyone tell you that you should stop eating or exercise for 6 hours a day or take laxatives, or binge and purge. Those are all not the right answer. Sure they might give you quick results but they're unhealthy and as soon as you stop those routines you will gain all that weight back plus even more. And it's a dark path that you might not even be able to get out of that can lead to death by heart attacks (even young people!) or malnutrition. So...for a healthier way...(I'm not assuming you were thinking about this, just wanted to state the obvi)
The best way to lose weight and maintain a healthier lifestyle is really just to eat right and exercise. This does not mean completely cutting out every food or drink you love, but instead learning self control and limiting yourself. It's okay to treat yourself with your favorite foods every so often, because if you cut them out cold turkey, you'll more than likely end up caving in at the end and giving up. Make small adjustments to your lifestyle by adding more fruits and veggies, and fiber!! Fiber is really good for you and gives you a healthy digestive system if you know what i'm sayin ;) Exercising for 45 minutes to an hour a day for 4-5 days a week will make you healthier, feel good, and help you slim down. Here's some tips I would give you from the experience I've had with dieting...
1. If you're a soda drinker, limit yourself to one every once in a while instead of one with every meal. That alone will save you tons of calories. And even drinks like gatorade and vitamin water should be cautioned bc they are sugary and have just as much calories if not more than a soft drink.
2. Fiber, as I mentioned above, is a great thing to have in your diet. You can find this in vegetables, some fruits, healthy whole grain wheat breads (Nature's Own is a good brand), and even in delish granola bars (Fiber Plus Antioxidants in chocolate chip flavor is really good!) Oranges have tons of fiber in them, so you can have one or 2 of those a day. It's healthy and it's pretty good too.
3. Smaller portions are important. If you want to treat yourself to some pizza limit yourself to a piece then have some fruit or a salad (but watch out for dressings and other condiments that have more calories than you think).
4. Drink lots of water! It won't make you drop weight on its own, but it cleanses your body, gets rid of toxins, and gives you healthy skin!
5. Very salty things will make you retain water, thus making you look bloated! So look out for the sodium amount on the back labels
6. To lose weight try exercising for 45 min to an hour a day. What I would do is to do some cardio for 30 minutes (brisk walking/jogging/running on treadmill, running outside, elliptical trainer, swimming, Zumba classes, tumbling, or some intense dancing) then use the rest of your time doing strength training. If you want you can focus on a certain area each day. Maybe one day do your cardio then do a really good ab workout. Then the next day do cardio plus legs, etc etc etc.
7. Don't overwork yourself with your workouts. If you do that your body will get tired and you might give up. So if you're feeling just wayyyy too overworked, take a day off and relax but make sure you get back on track the next day! You aren't a robot after all.
8. Eat a good healthy breakfast everyday! You could try a slice of whole grain wheat toast with some jelly, some yogurt (I like Yoplait light), or some fruit with a big glass of water or fresh squeezed OJ. There are lots of healthy and yummy cereals out there too (I like Mini Wheats strawberry or cinnamon streusal) with 1% or fat free milk. There's also good granola bars (Nature Valley or Fiber Plus Antioxidants)
9. Try to count your calories. Every food you eat should be labeled. BUT make sure you're not UNDERdoing it. For a teenage girl you could eat anywhere from 1000-2000 calories a day and be healthy. If you starve yourself and only eat around 500 or so, your body goes into what I call "starvation mode" and it holds onto fat stores in your body, so the next time you eat it will store that as fat as a survival method. So make sure you're getting enough calories but fill those calories with good, healthy, yummy things!
I know this is a lot to read, but I know what you're going through and how it feels. Seeing from your picture you look perfectly fine!! But if you would feel better then there is nothing wrong with a healthier lifestyle as long as it is healthy and not dangerous!! I followed those tips above when I tried to diet and lost 10 pounds in one month. Don't expect super speedy results, because those won't stay off for long. Slow and steady wins the race!! Good luck :) (again sorry this is so long, i just wanna try to help)