My dentist once told me that I obviously have viking blood. (He was right; I'm essentially half Scot and half Russian.) I am also a diabetic. I'm not alone. Roughly a third of Americans at this point are either diabetic or on the road to diabetes. If I ate the kind of carbs this guy eats, I'd have to load up on hundreds of units of insulin, and I'd never lose a pound. That's not speculation, I've tried that sort of diet. (Was a vegetarian for years, and couldn't lose weight on a 1200 Calorie vegetarian diet. And I was ravenously hungry and depressed all the time.)
Instead, the diet that has worked for me (very successfully) has been cutting the carbs. Most of my calories come from meat. I eat 4 or more eggs and bacon for breakfast. I quickly learned, by following my blood sugar meter, that I simply could not tolerate the 200+ grams of carbs that the government recommends. Since making the decision to follow my blood sugar 100% and ignore studies that, at best, present an average of what worked for someone else, I've lost well over 100 lbs. while increasing my lean body mass. My trigclycerides, once over 1000, have plunged. My HDL is high, my LDL is low, and most importantly my last A1c (a measure of blood sugar over time) was normal for a non-diabetic at 4.9%.
I'm glad his diet worked for him. It wouldn't work for me. No doubt, my diet wouldn't work for him. And that's ok. The notion that there's one perfect diet for everyone is virtually idiotic. And, most importantly, it doesn't work. That's not to say that there aren't some useful general principles, some patterns that are more likely to work for you. But at the end of the day it's your health; take the time to figure out what will work for you.