My relationship was already getting into trouble so
when my ex started laying on the pressure to lose weight I ate more just to spite him. I resented him laying on the guilt and felt horribly unattractive, resentful, etc. Don't do that to your relationship. Lead by example and don't make an issue of it and he may decide to follow. If he does, quietly accept it rather than making an issue of it or it may backfire. Just my 2 cents.