Being a loser myself...
having just hit 40# gone from me, and planning on about 15 more, I can say with confidence that 2000 calories/day, and an hour on a stair-stepper/day, will, in perhaps a couple of months, give your friend a surprising number of previously unavailable options.
I'm wearing jeans now that I haven't been able to fit into for years. Gone from XL to L in t-shirts. It's taking some getting used to, but I'm doing that with a big grin.
I have no suggestions for him if he wants to stay fat (let's quit with the euphemisms) except to be sure that his will is up to date. If that seems a little cold, so be it.
Your "friend," RKBA Bob, oughta consider losing his extra baggage. If I can do it anyone can. He should join a gym, hire a trainer, quit BS'ing himself, and start with the aches and pains.
Prevents strokes, diabetes, heart attacks, probably cancer, makes it possible to use IWB holsters, not to mention being able to out-drag deer outa the woods compared to someone 20 years younger. It's a hassle and a struggle and no one can do it for you (though they can--and do--offer encouragement, and compliments) but let me tell you it is WELL WORTH THE EFFORT!!!
Good luck.