@Adamantspants
You keep repeating that some people don't find overweight people attractive.
What you can't grasp (so to speak) is that some people might still be attracted to someone if they gained weight. Even if that wasn't their on paper preference.
Again, some people might want a partner who could find them attractive if they gained weight. Not a huge leap of understanding.
Saying basically, lose weight or I don't want to shag you is a big turn off for some people. Perhaps almost like fat is a turn off for you.
Also, do you think the Op's partner is really wanting them both to embrace a new healthy lifestyle together and to be a team in that respect?
Or is it... you do everything you already do which makes you knackered but exercise on the top of that, buy in all the healthy food, cook it, listen to me whinge about it, watch me buy and eat unhealthy food while you nibble spinach leaves etc. Basically he gets the smaller wife he wants and does wtf ever he pleases. That's what a lot of men really mean by "we" should get healthier.
FWIW myself and my partner have recently improved our health/lifestyle and we worked together to do it. That involved things like saying, oh let's have extra veg tonight, I've got it ready so you can cook it, let's go for a quick walk etc. Not, get thinner or I won't fuck you.
In sickness and in health...as long as it's a size 8-10 as per pre-vanity sizing.
@Adamantspants In short, if you LOVE someone, then you support them. You don't just say, oh I can't get "the horn" for fat so do one.
No one is suggesting having sex with someone you aren't attracted to.