I struggle with this a lot myself. You really have to practice the principles of Al-Anon, which is the group for the partners of alcoholics. You can't change another person. You can only live your own life and let others live theirs and find their own way.
I'm not very good at this sometimes because I get fed up with the undeserved push-back and blame I get. I really don't think serving salmon and steamed vegetables is the cause of another person's arthritis and chest pains, but I get blamed for it because once in a while I serve red meat. Nevermind the man chooses to eat red meat and also chooses to serve it sometimes. It's much easier for him to blame me when I do it once in a blue moon than take responsibility for his own choices.
However, I'm no saint because despite knowing better I sometimes will send him a link to a video or something to defend myself. I really shouldn't do it. I should just mind my own business and keep doing what makes me feel terrific, healthy and strong and hope someday he meets someone else who can change his mind so he can be the healthy, strong person he ought to be instead of the chest-pain-riddled, arthritic, sad-sack that he is now.
A friend of mine told me how his wife started attending FA (Food Addicts Anonymous) and lost 130lbs. Her depression went away. Her health improved. She felt happy and no longer squabbled with him every night. She attended these meetings (they simply give up sugar and flour) for over a year. Meanwhile my friend continued to overeat on pasta and other flour and sugar goodies all the time and continued to see his health decline, continued to feel grumpy and pick fights every night etc. It took over a year before he finally wondered if maybe his wife was on to something. Then he decided to try it and within a week his blood pressure was normal for the first time in decades, and over time his mental health improved, he stopped picking fights, they have a happier marriage now and both are thinner and happier and healthier than ever. But it took more than a year of her being patient. And I don't remember what was the ultimate catalyst for him, but it certainly wasn't her nagging him, that's for sure.
Female, 5'3", 48, Starting weight: 163lbs. Current weight: 135.
Starting bench press: 30lbs. Current bench press: 75lbs.