Carb the F--- up. I.e. pour huge quantities of sugar on your food/in your drink, eat large plates of plain white rice, drink litres of Sprite and eat 30 bananas a day. You'll soon get the message if you watch him - he repeats the same thing over and over. Fat makes you fat, sugar makes you lean as f---. Not lean enough? Eat more sugar, look at me, 2% bodyfat. Etc. etc.
He exercises, so he can get away with that and doesn't gain weight. Also eating little fat he has more room for carbs in his diet.
If he was eating a lot of meat, animal fats and cholesterol he would not get away with it because you can't lower your cholesterol levels the same way you can burn off calories. He could be dead from a heart attack at age 60 despite his fitness level.