As he's rich and depressed he'd probably under some psychiatrist who has got him on medications,these medications routinely pile on the pounds, fukk knows why anyone takes them, getting fat does wonders for someones depression. Psychiatrists especially the private ones,that cost shedloads to see are basically legal drug dealers. I mean they are basically guessing what causes depression anyway and how to treat it. What other bit of medicine relys on educated guess work? And sometimes these meds can actually make the problem worse.
The key to depression,isn't meds,but to work out what bit of your life is causing this in the first place and then change it. So if it's a marriage ,get out of it, a job,find another, a bad abusive childhood? seek counselling with a professional with a good reputation. If it's your lifestyle, change it. The vast vast majority of people with depression and anxiety don't need psychiatrists and don't need medication.