You should also eat oatmeal on a very regular basis...contains lots of fiber and helps to lower your cholesterol. Drink about a half gallon to a gallon of water each day (depending on your size/weight) to avoid dehydrating, and lay off the sodas/alcohol (you shouldn't be drinking or smoking anyway). The best thing is to base your diet around LEAN meats (skinless chicken breasts and fish - try to limit beef and pork as they are very fatty and high in cholesterol) and plenty of fruits and vegetables. Peanut butter is good, and if you eat bread, it should be whole-grain (low-carb bread is even better but it costs more $$$).
At 15, you are still growing so you should definitely talk to your doctor for his/her advice and input since they know your specific genetics/metabolism, etc.
To lose weight and be lean and mean and learn boxing is best.
Eat chicken breast and vegetables and a little bit of white rice for flexibility. finish every meal with a small cup size of boiled oatmeal. Eat like this for lunch and dinner. Have some fruits in between meals as a snack.
But before working out...eat a spoon of peanut butter or a small bag of potato chips to get a little fat in you so that you can trick your body to burn away the reserve fat in your body, since more is coming in.
Eat anything that grows in the ground/ trees and anything that you can kill. This is all of your fruits, vegetables, meats and water.
Cut down on sports drinks, whole milk, candy, junk food.
food . potatoes vegetables fruit meat ,are all examples
