Will weight lifting(low reps, high weight) and taking whey protein also help me lose fat?

Im a boy, age 15, 145 pounds, im not that fat im actually pretty athletic but i have a little "chub" on my belly. I've been starting to eat more lean meat(and i get a lot of protein from it), veggies, fruits, egg whites, etc. Im not dieting, just eating a healthier diet. I barely eat any bad carbs, only good carbs and only moderately. I drink a protein shake(100% whey protein from EAS) before and after my gym workouts. What else should i do if im trying to gain muscle and also lose fat?