Wife got FAT and I am not atrracted to her anymore?

Wife got FAT and I am not atrracted to her anymore, we have been married for about 7 yrs and have 2 kids, both her and I work, but I find time to exercise and at least try to look good, but she doesn't try, all she does is talk about these scam wieght loss plans that don't work like south beach and Atkins, she has gained at least 65 pounds since we have been married and I want the girl that I married back, not someone who relies on goofy weight loss programs that son't work, I asked her if she wanted to work out with me but says she is too tired