The only suggestion I have is to let him know how you FEEL about his health issues.

It seems like you are fearful of being a widow too young. So tell him that.

My BIL died on New Year's Eve. It was his second marriage; my sister died when she was only 50. But his wife has now buried two husbands. BIL was a wonderful person. But he was morbidly obese, T2D, had had numerous cardiac catheterizations, and, in the end, his cardiologist fired him, because he would NOT follow recommendations for eating or exercise.

You may hurt his feelings. But he's killing himself, isn't he?