In theory, yes such an individual could loose some body fat and gains some strength, though there is not enough information to say he WILL do one or both. If he is successful, of course he will be in a lower weight class, but lift heavier, thus he would improve greately at his sport. If I were going to eat a carb, it would not be potatoes though, if one's goal was a loss of bodyfat, change it to oatmeal. It has a much lower GI and II, as well as having more fiber, B vitamins etc. Use whole eggs instead of egg whites. Most of the nutriants are in the yolks. Egg whites are not that great of a food. They are low on nutrients and have no fat. If one is attempting to loss bodyfat, one most focus on the quality of calories consumed, meaning they need to get the best nutrition possible on the limited calories they are taking in. Egg whites would not be my first choice of foods for this.