The underlying problem here is his mother's failure to act when he started putting weight on. It should have set alarm bells ringing when he started to get unusually big and she should have seen a doctor. Any parent would know that there must be a medical or biological issue when a kid that age starts to get huge like that. Teenage kids have lightening fast metabolisms and it's pretty impossible to gain that much weight through eating alone, even sat in front of an xbox all day. I'd say that this poor kid's eating habits are no different from most other kids his age, except his weight problem exacerbates his appetite. the fact that the mother is too idle to cook proper food doesn't help though, but then there are thousands of parents like that in the UK and their kids aren't that big. What a sorry story.