This is a great thing for you work on with your W. If you get together on menus and such then you connect on something that is not so emotionally loaded - in counseling it is called "building rapport." In my view it doesn't hurt anyone in the family including the kids to learn to eat a bit better.
HP:
My H struggles with his weight and sometimes gets upset about it - he runs triathlons to motivate himself. He is a very big guy at 6'2" and 240lbs. He doesn't try to win the races, just do better than he did the time before.
I control what I eat much better than he does. He eats when he is tired and stressed much more than I do and he hates vegetables. HP - I have to forcefully tell H that I DO NOT want pizza, ice cream, or potato chips at 11pm while watching tv on the couch. Makes me crazy. He is Italian so pushing food on people is a birthright.