DH lost 4 stone and his unbearable I'm-going-to-stab-you-if-you-don't-shut-up-you-bastard-type snoring stopped almost as soon as he lost the first stone and a half. He's put a stone back on since but the snoring hasn't returned, thank the Lord!
I wouldn't waste energy being hurt over his 'refusal' to lose weight, I doubt VERY much that he's making a conscious decision not to lose weight so he doesn't have to come to bed with you and it's unlikely that he wants to snore - I suspect you're taking this very personally (having read your breast reduction threads you do have a tendency to make it all about you, don't you?).
Please don't nag him, that will simply make him resentful and rebellious. He's an adult, only he can make his own mind up. And tbh it sounds like he's taken this on board, he's cut down on drink and started walking - you really can't say he's not making an effort!
What you CAN do, however, is give him smaller portions (when we were losing our weight it was a revelation how little we actually needed to eat, I was feeding us both enough for two, no wonder we were overweight!). If, like DH, he's the sort of man who likes a full plate and feels deprived if it's only half full, cut down on the potatoes/pasta/rice element of the meal and replace with loads of green veg/salad. Portion control is key.
If he's still hungry thereafter, make sure there's no cake/biscuits/crisps in the house but lots of healthy snacks - fruit, or veg strips and low fat dressing as dips, which he can snack on to his heart's content. Not only good for him but healthier for you too!
Good luck