alright... your biggest meal of the day should be breakfast, because no matter what you eat, it WILL be burned off by the end of the day. basically, eat a lot of proteins. proteins are a big one. you can get those from meats, fish, protein shakes and specialty bars. you should also eat a LOT of greeen vegetables and olive oil. for the exercise, work on a lot of muscle machines, or do various squats, situps, lunges, and even though you are thin, you should still do some cardio, even if it is just soimething like an ellyptical, which is really GOOD for building muscle in the buttox and legs area!hope i could help
