The truth is, it's none of those things. I am just unwilling to indulge people's fantasies on this issue, because I've lived through it having been clinically obese myself in the past.

>I find it supremely hilarious that you refer to the person's own body as an external factor.

It's external in the sense that we have no control over our DNA, which is implicitly being blamed when one speaks of one's own predisposition towards weight gain. It's not that funny.

Thermodynamics doesn't lie.

Operate at an energy deficit and I guarantee you'll lose weight.

Is it going to feel horrible? Hell yes.

Thermodynamic doesn't lie... but it isn't even close to being the most important factor at work.

A Pound is 3,600 calories. I can easily eat 1,800 calories over my maintenance requirement.

Do you think in one year I am going to gain 180 pounds or .5 pounds per day?

Thermodynamics is only involved at the simplest levels. Hunger and satiation are regulated primarily with leptin, not thermodynamics. Fat storage is controlled primarily with insulin which is itself regulated by various endocrine system components. Thermodynamics is only involved at a level far below complex systems control dynamics.