I see what dboxing is getting at. The argument has progressed from calorie-in-minus-calorie-out CW vs. Primal to one of the finer points of Primal. We can all agree that if those calories had come from sugar instead of fat, then cutting the sugar would either make weight loss faster, or cause no weight gain at all.
But what if somebody has already cut all the sugar out and is already primally trained to burn fat as fuel, i.e. all other things being equal. Does the equation then convert to weight loss = FAT calories out minues FAT calories in? In other words, if you give up 12 cups of bulletproof coffee* do you lose an additional pound of fat? Or does our metabolism automatically ramp up to burn whatever fat we feed it?
Mark and others seem slide around this question by arguing that this is moot point: that our stomachs and brains are leptins become so satisfied by fat that we just don't feel like eating more, that is, we self-prevent eating excess fat calories. The Bulletproof exec cites his experience, where he consumed enough to yak butter in two years to gain 400 lbs or so but didn't. Maybe it was all the walking in the mountains? I don't know. The calories-out part of the equation is still a mystery.
*3500 calories/ pound of fat divided by 12 cups BC at ~300 cal/cup.
BC cal count: 2 tbsp ghee (250 cal) + 1 tsp coconut oil (50 cal)
5'0" female, 45 years old. Started Primal October 31, 2011, at a skinny fat 111.5 lbs. Low weight: 99.5 lb on a fast. Gained back to 115(!) on SAD chocolate, potato chips, and stress. Currently 111.