has the doctor checked his thyroid?
Your son's experience sounds EXACTLY like mine when I was little, and it turned out that I had a thyroid problem inherited from both sides of my family. I was a little chubby when I was 5 or so, and my family just called it "baby fat". But by the time I was 8, I was clinically obese. And this was in the early '70s, back when there were hardly ANY fat kids. It was torture--and I had done nothing to "make" myself fat. My physical system just went off the rails, and I started gaining weight like crazy, no matter what I did. Does that sound like your son?
My pediatrician tested my thyroid regularly, but I never received any medication. I don't know why, as nobody explained things to the 8-year-old they were sticking with needles. Maybe the doctor thought I'd grow out of it--but now we know that people don't "grow out of" a thyroid problem, as it's a chemical imbalance just like any other that impairs a body's ability to function properly.
Like your son, my diet wasn't bad. I was less active than your son, but that was because of other health issues (low blood pressure and a D deficiency that made me woozy if I was too physical). His high level of activity and decent diet should mean that he'd be a "normal" size. (Snacking is a problem, but if his metabolism were normal, it shouldn't be that much of a detriment. I have a normal-weight son who eats constantly and is less active than your son, and he's not gaining weight.) I was put on a strict diet and exercise program when I was 9, and it did NOTHING. My body did NOT budge for anything except puberty, when I slimmed down practically overnight, and I stayed skinny well into my adult years.
However, I found out later, that was because I had swung from hypothyroid (TSH too high, metabolism too slow) to hyperthyroid (TSH too low, metabolism on fast-forward). This happens with lots of thyroid patients (the pendulum swinging between the two extremes), and it's NOT healthy--contributes to weakened heart muscles in the long term. (Now I'm back to hypo and overweight; the pendulum swings don't stop.) Do you know if there's any history of thyroid problems on your husband's side?
The bottom line is a child who eats normally and is physically active should NOT be obese without some underlying medical problem that has gone undiagnosed.
I would urge you to request that your son's pediatrician check his TSH level as well as his free T3 level (thyroid hormone). Be warned, however--most doctors don't know the first thing about thyroid problems. Most just check the TSH and declare it "normal" if it's in the old acceptable range (between 0.5 and 5.0), which doctors who understand thyroid problems now have rejected as too broad. The new acceptable range is much more narrow. (As an adult, my TSH was 2.5 and I was half dead. It turns out that I function best when my TSH is around 1.0, which some doctors consider too low.)
Likewise, most doctors don't know how to treat thyroid problems, especially in children. Like I said, they expect them to "grow out of it", which does not happen. Thyroid must be treated with medication to balance the body's chemicals. However, most doctors will prescribe Synthroid, which is just about useless. Natural thyroid is better than synthetic by far, but lately natural thyroid has been difficult, but not impossible, to obtain. But that's another story.
In the meantime, you can read more about thyroid problems here:
http://thyroid.about.com. See if the symptoms sound familiar. Most important, don't let the pediatrician brush you off. If you feel that there's something wrong with your son, hold his/her feet to the fire until you get to the bottom of it.
Best of luck. And feel free to PM me if you have any questions. :hi: