How concerned should I be about my boyfriend's health?

My partner is a 34-year-old male, former colleague athlete, used to be fit, but has never been super lean. He plays recreational softball but other than that is not super-active, although he works out and runs sometimes when the urge strikes him. Not with any consistency, though.

He inherited a tendency for high cholesterol from his father, but is unable to take statins because he suffered muscle degradation and something called a parathyroid adenoma, for which he needed surgery. Since then, no statins, his only medicine is something called Welchol, which is a chalky drink mix that binds to fat and tries to keep it out of the bloodstream.

I remind him about his diet often, but I can’t force a grown man to eat healthy. He despises kale and quinoa and when he’s at work, I know he sneaks hotdogs, subs, pizza and other fried, fatty foods. He also makes poor food choices when he drinks, even when I’m standing there BEGGING him not to eat the greasy wings and fries.

I’ve never had to worry about fat content since I prefer low carb and I don’t have high cholesterol. But since meeting him, I’ve changed my cooking habits to meet his dietary needs—turkey meatballs instead of beef, chicken instead of lamb, olive oil instead of butter—always looking for ways to cut fat content.

Today he had a very bad cholesterol test of 242 and 165 LDL. He vows to be better about eating well and exercising but I’m very scared for his well-being, especially since his motivation tends to peter out. He’s 231 lbs at 6’2 so it’s not like he’s grossly overweight, but clearly something needs to change.

I adore this man and we’d like to get married in 2018, but now I’m terrified of being a young widow. I’m only 27.