Has your weight loss put strain on your relationship?

A couple weeks ago my boyfriend and I almost broke up - as a matter of fact, I thought we had. I later came to find out that he was basically insecure because I started working out and eating clean (which he had been encouraging me to do) and was acting out because of it. He felt like I wasn't making enough time for him when I first started working out, because I started out hardcore (and have stayed that way). I think he also has some feelings about the fact that he has put on weight since we got together, just like myself, but now I've lost all the weight I put on, plus I'm waaaaaay more fit then I was even before we got together, and he is still the same. I've made an effort a few times to ask him to work out with me, but he always passes. I've even brought workout gear into the house for him to use, and he's used it a few times, but nothing significant. He pretty much eats like **** too, but he is one of those people who thinks he eats healthy, when that couldn't be farther from the truth. I would like him to get into better shape as well, just because I see how much getting healthier has done for me - my anxiety is totally mellowed out, I'm happier, I look better, I feel better. It's literally all good. I want him to get healthy, and into better shape, and to eat better, too, because I know it would not only do great things for him, but it would do great things for us as a couple. ...but more so, I don't want him to continue to be insecure (or whatever) about the fact that I'm getting my *kitten* in shape. Has anyone else experienced this? I am honestly worried that if he doesn't kick it into gear, it might spell the end of us. I mean, it nearly has already. How do I keep us from growing apart because I'm making my health and fitness a priority?