[Barefoot]

If he is willing to see a Psychologist, that would be a good first step.
However I've rarely seen a man who seeks out counseling unless a woman has a gun to his head.
I have friends who attend Weight Watchers, and swear by it. Not only to lose weight, but to maintain the weight loss.
They tell me that the WW Program teaches you how make good nutritional choices.
Perhaps you could phone around and find a WW group that has some male members.
I think there are also TOPS groups in The Villages.
Losing weight in a supportive group environment often helps people stay on the lifestyle changes necessary.
Most of all, he won't change unless he is committed to losing weight.
All your good intentions in the world won't change him, it has to come from within.