How to lose body fat without losing weight?

If you do muscle-building exercises, your body will lose fat and gain muscle. When gearing up for track, I ended up gaining a little "weight" but it wasn't fat, it was muscle. Muscle exercises are squats, bench workouts, etc. Balance those with cardio workouts and you'll gain mass, but lose fat at the same time. ALWAYS talk to a trainer or your doctor before you start a new fitness regimen, especially if it's going to be rigorous. Good luck!