My friend is in a very similar position.
Her DH is morbidly obese, but he does nothing to help himself. 10 years ago when they met, he was early thirties, 32-34 waist, fit, healthy and quite an attractive man. He's ex squaddie so was always quite active.
Fast forward 10 years, he now drives a hell of a distance to do his job, upwards of 4000 miles a week
some weeks. He eats crap, takeaways every night, no breakfast unless he stops for a fry up at motorway services en route.
He's now maybe 8-10 stone overweight
he looks twenty years older than he actually is (43), he sweats like a leaking sponge and shuffles like an old man as he can't walk properly - he waddles more than shuffles actually.
To cut to the chase, he is repulsive, his wife thins so, I think so and yet he is deaf to the comments and suggestions to take more exercise.
His wife is desperate to have back the man she married and has resorted to blazing rows to get him to listen, but to no avail. If he doesn't take action soon, i fear she will leave him as she is so worried about finding him dead after a massive heart attack.
She cannot understand why he won't do it for his DDs, and instead chooses to spend his nights in a hotel watching films or surfing the web, when he could make use of the very extensive gym facilities available to him.
Worse than this, is that he will bollock his wife around the block for treating their DDs to a McDonald's after their swimming lessons and he doesn't even see the irony. :(