Spousal "Support"

MrsG2

A boyfriend can get on board or get lost. There's the door, buddy, don't let it hit ya where the good Lord split ya.

That's my first reaction. HOWEVER, in deference to the apparent fact that you love this guy and want to make the relationship work, talk to him. It's not unusual for a man with a heavy partner to fear losing that partner to someone else (read: a younger, fitter man) when the partner starts losing significant weight. You look better, you feel better, and in his mind you may deserve better. If that's the case, smack him one upside the head for being an idiot and reassure him that you are doing this to be healthy, not so you can land a "better catch".

Honestly though, if he can't resign himself to a slimmer, healthier you, then you really need to do some hard thinking about whether he's the person you want teaching your kids what a good relationship looks like.

Well said.