on being overweight

My fifteen year old boy badly needs to get in shape. At his age now, aside from being lazy and couch potato, he is also overweight by twelve pounds too. I am afraid that if he continue to eat so much, and with no sports activities at all, I am afraid he'll gain more weight. Worst, his legs might not be able to carry his body weight and might end up wearing acl knee brace for support. Very bad. Hence this summer, I've decided to do something! I enrolled him to a basketball clinic to keep him active, and help burn fats. Wish me luck, hope it works!