Why does my kid refuse to lose weight?

While I understand your concerns (potential teasing, health concern, etc.), it is not uncommon for a boy of that age to pack on a few extra pounds as they go through this age - hormones, etc. - before they have another growth spurt (also typical at this age). He could very well "even out" in the next year or two. You could institute a daily walk/run/jog or involve him and any other member of the family that wants to do it with both of you in a new exercise class - kick boxing, ZOMBA (okay, maybe not that), or something else. If you make it an issue it becomes an issue. Talk openly about better choices to make in your daily food intake and how it is important to be healthy now and throughout life to avoid problems in the future. You certainly can't control everything he does, eats, etc., but you can be aware of it and make the changes yourself too. Nothing better than a good role model, Pop!