How can i add muscle and lose stomach fat simultaneously?

3 things to do: First is obviously a balanced diet. Second--to gain muscle, you must do weight-bearing exercise/lifting/squatting etc... Third: fat around the waistline is tough to trim, so ab crunches/twists (kick-boxing is incredibly effective but tough to do). Slow, persistent/commitment is needed to build a well-balanced/healthy body. U are doing it for yourself, so take the time and do it well. Good luck.