Yeah but, despite all of that, (none of which I read, I'm sure it's all true though), it is a natural law of the universe that you cannot get more energy out of a system than you put in. Regardless of all other factors, if you consume upto your daily maintenance calorific intake, you cannot gain weight. If you consume less, you WILL lose weight. Whether external factors or pressures prevent you from managing your calorific intake correctly in another discussion, but the laws of thermodynamics don't take a break when it comes to health and nutrition.