I believe that his family must come forward and fight the problem. Even if he weren't obese, he would still be a huge kid. He is 5 feet tall at age 8. Diet and exercise is primarily what it takes.

If he has lost 20 lbs. on his diet he is headed in the right direction. If he is doing that under his mother's supervision, all the better. Keep him with his family.

Sometimes I think government types carry things too far. There is discussion of anti-spanking legislation here in California. Although I never really had to spank my daughter, I never equated a reasonable spank on the behind with beating a child.