Sandy Koufax was a Hall of Fame baseball player, but you probably know that. He has been retired for decades but has stayed in amazingly good shape.
He doesn't really push a diet with his name on it, as far as I know at least, but he once told an interviewer how he stayed so fit. He orders anything he wants to eat but leaves half of it.
Cheeseburger with mushrooms and grilled onions? Fine, leave half of it. Fries? Leave half of them. Dessert of fudge pie? Your poison, but leave half of it. Beer, wine, steak, ice cream, etc. etc.
For those of us with high metabolism, lean body types, and very little willpower, this works pretty well. Try it some time, and you'll be pleasantly surprised, especially when so many restaurants serve too-big portions anyway. My roommate is on Nutrisystem, and I can say the Sandy Koufax Diet is a whole lot more tasty.