gday, ive just turned 17 and when my field hockey season finished i gained alot of weight. i went from training of 6 intense hours a week and 4 hours of games to nothing. i kept eating the same stuff as i did when in training and i gained alot of weight. fatty foods you should stay away from, there not good at all..carbs are good for you if your in heavy training ect but are just as bad as fatty foods if not burnt hence the atkins diet (no carbs, high protein diet)..
i have no set diet and have trouble avoiding all the bad foods but i try and do every day is try stay away from grainy foods (breads/pasta/ect.) and fried foods..eat lots of veggies,salads and meats. and also minimise sugars. i usually eat carbs 1 hour before i goto training tho.
remember, when packets of foods say "no or low fat" they usually replace it with high sugars/carbs so try and avoid them.
an example of a nice healthy meal for me would be. a grilled steak and a nice salad made from cucumber, carrots, iceburg lettuce, snow peas, alfalfa sprouts.
i also usually suppliment it with differnt salads and steaks for chicken breasts with a nice lemony sauce/marinade.