My husband is a type 1 diabetic but wasn't doing all he could to give himself the best care. I didn't ask him to modify his eating when I had surgery, but he did and he lost weight like crazy. He also does all the cooking, so I think that made it easier for him to make the jump. We do super high protein/low carb dishes and snacks. He chose to come to the gym with me and that was a huge game changer. We now do that and all kinds of activities like bowling, disc golf, etc. together. All of our friends joking refer to us as "the power couple" since we're both healthier, more fit, happier, and super active.
Best of luck to you and your husband on your journey!