exercise more and eat less. Don't eat as much red meat or carbs because they have quite a lot of fat. Eat veg and no fast food places. I would recommend doing sport football, hockey, tennis or badminton. If you want to work on your legs, cycling and if your arms i would do swimming of you want to work of your whole body then do the first couple i suggested. press ups are good for arm strength and sit ups are great to loose weight in your stomach.