How to secretly inspire your loved one to lose weight?

I love my husband more than I could express, and when I married him 5 yrs ago, he weighed at least 50 lbs less. He was already a big guy, which I love him for who he is anyhow, but now I'm seriously concerned about his health! He's at 317 now. His dad has diabetes, and a slew of other health problems due to being overweight. I just had our 3rd baby, so I'm overweight also, but I've been dieting and exercising, and I've lost 16 lbs, and still going steadily. He's getting lazier and lazier, leaving me to have to do more and more to pick up his slack. I know if he loses some weight he'll have more energy, he'll feel better, and he'll be happier, but I've already told him I'm worried about it, and he agreed with me, he wasn't offended, but he's eating gmore and more, like he's getting worse! I hoped that with me losing weight, he might just want to also, but I know that this was my decision, not his... so what else can I do? He had his appendix taken out last year and that Dr told him that the type of body fat he had was going to kill him. We've got 3 kids, he needs to be a better example for them!