It's so difficult. My husband is very big now, in the obese rather than overweight category. I still love him, I still fancy him (perhaps a tinsy bit less) but I do wish he would shift the weight. He has a huge belly and it goes everywhere first.
I have tried cooking healthily, tactful remarks, we have talked openly and honestly about weight. Sometimes I snap at him now 'why are you eating that?' when he is on his 5th donught.
Who knows if it was really her insulting him that made him change, after all, she'd been expressing her displeasure for 20 years. My guess is that he simply decided he didn't want to die young for himself, and has been humouring her delusion it was all down to her ever since.