Even assuming he makes the VERY modest goal of 12 pounds in 3 weeks, as soon as he leaves, he'll go back to his old bad habits and put all the weight back on. He doesn't seem like the sort that has the will power to stick with a program like Pritikin for the rest of his life . . . it takes a quasi-religious experience to make that sort of extreme lifestyle change, and "religious", quasi- or otherwise, is not a word that leaps to mind when I think of him.
I agree 100% Mom. In order to quit any addiction (excessive eating, drinking, drugs, gambling, etc) many people have to hit "rock bottom" before they will change their ways.