Can acupuncture help with losing weight?

Was just wondering if it helps people lose weight? My son is very overweight and I'm trying to help him lose the excess pounds, we speed walk 3 1/2 miles every day, and he has 2 one on one sessions of Thai kick boxing a week. We swim for an hour once a week and he also has 2 hrs of P.E at school. I measure out all his food and have stopped giving him any money. All his meals are cooked from scratch with fresh veg and fruits for dessert with the occasional slice of homemade cake. But the weight doesn't seem to be shifting. I'm not an idiot and I know he does manage to sneak other foods because I find wrappers in his bedroom. I walk him to school and they aren't allowed out at lunch so he would have to buy sweets on the way home and eat it really quickly! He's 14. And only strarted gaining weight when he was around 10. What else can I do as I'm really worried.