My little brother is 13, and he is overweight, to the point he weighs 218 lbs already. He will not exercise, and eats whatever he wants. Junkfood, soda, etc, and it just keeps getting worse. My sons on the other hand, are in the 90th percentile for weight of kids in america (meaning they are bigger than 90% of kids their age) but they are also there for height, they are just big boys. They eat right, and get lots of exercise, because I don't let them watch tv all day, only for 2 hours. The rest of the time is spent on homework, and playing.