As someone who struggles with weight, I think your DH is being ridiculous and childish. My boyfriend has a faster metabolism than I do, and can eat what he wants. Is it fair? Heck no, but then neither is life. I wouldn't dream of asking him to modify his intake just to help me (he already does that with alcohol, which is even more essential in my case.) I would just tell him that this is his issue to deal with. Maybe he could eat one cookie and just stop at that-one cookie doesn't break a diet. Five do.