Probably why this diet may work is that he has eliminated the big 4 food groups that cause people the most problems: Grains (except rice), diary (except butter), soy and corn. There are also no legumes or nuts allowed. Notice also that all the foods recommended are basically all natural, whole foods. Almost like a paleo diet with hardly any veggies, nuts or seeds and only selected fruits. This would work for those who love their potatoes and/or fruits as long as they didn't trigger huge cravings. In those portions recommended, you would have a hard time going over 75 grams of carbs a day anyway. Besides 1/2 lb of fresh meat at each meal with fat would leave you quite satiated.