[jjindev]

I am not a nutritionist or a biochemist, but as a guy with an old BS Chem and a general knowledge, it does not surprise me to hear (again) that we are not all bomb calorimeters. We have long known that our metabolic pathways are neither uniform nor universal. There is no surprise there. When you eat fat, carbohydrate, or cellulose, different things happen.

Thus, I think the extreme "calories is calories" argument is anti-scientific.

Given the real complexity, I personally favor a varied and omnivorous diet, avoiding things both unnatural in their manufacture but also unnatural in their availability. A diet high in sugar is not natural. It would be very surprising if evolution and the evolution of our accompanying microbiome prepared us for it.