I guess I did something wrong when I posted the original question, because I never saw anybody's answers until now. Thank you gymdandee, shermay and brice 1967 for your responses. :) I think I was supposed to "add to watch list" and didn't.
I wouldn't necessarily worry about how many calories he is eating unless he is under the care of a physician regarding his diet. I'd suggest the young man eat a very balanced diet and drink plenty of water. The quality of food I believe is key. Good fruits, vegetables, nuts, lean meats are all essential in regular amounts.
Obviously exercise is essential. If he is exercising more, he'll probably naturally change his eating habits. (The body kind of tells us what we are needing) Make sure his diet is healthy... if his portions change a bit and he isn't gaining fat, I think everything will be fine.
A better start is to check with the childs pediatrician. Someone who knows him more intimately will be a far better source for information regarding his diet.
He is a growing boy - and will need all the 'good' food he can get.
Stay away from sugars, high calorie drinks etc. Plenty of water, and a well balanced diet.
If your Son is overweight, check out the Fridge, and dump the goodies:)
There are no hard and fast rules, but according to The American Heart Association, a 14 -18 year old girl needs about 1800, boys need closer to 2000. So you should adjust down accordingly for your 10 year old boy or girl. Consider 1500 - 1600 a day depending on sex, body size/height and level of daily physical activity. TV watchers need a lot less fuel than a kid who runs and plays all day long. Also the quality of those calories makes a huge difference. One candy bar will add up to 300 calories, the equal of consuming 7 small apples. Ask your pediatrician or nutritionist for a more accurate recommendations.