Noooooo, tell him you ARE an expert and charge him 50 notes for your professional advice.Purely because of the weight for the alcoholism (might be more accurate to call it dependency) if it is a bloke. Men don't do emotional comfort eating as much as women and not usually in the same way.
Over eating bigger portions maybe but not whole tubs of ice cream every night.
I'm not pretending to be an expert mate.