<human>: Can you condense the text into a few key points?

My fiancé has had psychological issues regarding his weight for most of his life. He was apparently overweight as a kid, with a family history of eating disorders, was working out and normal entering college, very quickly devolved into borderline anorexia, and has since gained 30 lbs in 3 years. He finally seems to be content with his life and his body--yesterday, we went to a water park and he kept his shirt off the entire time and wasn't sulking! But, he is now overweight again. 

I know that it's all ultimately up to him as it's his body, but I know too that spousal (or spousal-to-be) support goes a long way, and we are a team from here on out. When we weren't even thinking of marriage yet, he lent me the strength to overcome an addiction I'd been enslaved to since 10th grade, and he has sometimes-literally carried me through treatment for a chronic illness. 

It absolutely devastated me to see him starve himself and, briefly, reject me sexually because he did not want to deal with being naked and having another person see him panting/struggling physically exerting himself. I am so, so happy that he's happy with himself now, but I can't really relax about it. I'm worried that this is just another lull in which he complacently declines in physical health until starting all over again with hating and starving himself. Due to our different schedules, religious beliefs and taste preferences, our meals are completely separate, and even if they weren't, I'd need more than the month left before classes begin to learn to cook for him. I just don't know what to do. 

I'm terrified of him deteriorating again, I want to help him, and I have no idea how. Talking to him about his self-esteem, eating habits or workout habits is usually akin to walking on eggshells. This is the man I want to spend the rest of my life with and I love him dearly, please help me help him.
<bot>: Fiance has self-esteem issues and has had brushes with anorexia. He's confident and happy now, but is overweight again so I'm worried that won't last. How do I help?