Originally Posted by BigPoppi
It is physiologically impossible to store body fat from consuming natural fat.
Why? Purely on evolutionary grounds, it seems incredibly unlikely we would have evolved such a counter-productive physiology.
Fat storage mechanisms are there in mammals because they help survive periods where food is scarce. For any omnivore it would be incredibly inefficient to be unable to store energy from the most calorific of the macronutrients - i.e. dietary fat. A hunter-gatherer who could not convert natural dietary fat into body fat would be at a massive disadvantage compared to one that could.
Also, other mammal species seem to put on plenty of fat from eating fat e.g. cats, dogs and bears - minimal carb intake, high protein/fat intake. I suppose you could argue it's the protein, but again, why would mammals evolve such a strange metabolic quirk?
While we might find it easier to convert some foodstuffs into fat than others, the marvellously versatile human body can surely store all three.
If you ate 9000 kcal/day of whey and nothing else, and expended only 2000kcal, you would store fat.
If you ate 9000 kcal/day of potatoes and nothing else, and expended 2000kcal, you would store fat
If you ate 9000 kcal/day of butter and nothing else, and expended 2000kcal, you would store fat.
If we couldn't store fat from anything
that provides excess calories, we'd never have made it through the ice-ages.