It is this narrow minded thinking that gets people in to trouble. I can kind if see your point if you want to really stretch it. Yes, the body is going to generate the fat in large part from "calories" After all the whole body is really made from water and the food we eat if we think about it. But saying that more activity is going to make an overweight child thin in all cases is ludicrous. There are many metabolic disorders that contribute to weight gain. So these, as well as food intake could be considered co-factors rather than individual causes. What if the child had a hypothalamic tumor that is causing the weight gain and you tell the parent that they are bad because they are not making sure the child is getting enough exercise? What if the child is gaining weight because they are on steroidal inhalers for their uncontroilled asthma? And you want that child to go out and run in the pollen? Get real guy!!! Medicine does not fit in to a little compartmentalized box where everything is clearly black and white!!!