No, I didn't; that was another poster. However, if you think that is claiming that thermodynamics is wrong, you're misreading it. Instead, it's claiming that the usual argument people make, when they're referencing thermodynamics, is non-scientific.

(The real objection here is that chickens are not spherical. Or, less flippantly: that human bodies do not typically operate at a set efficiency with regard to thermodynamically available energy in food. The efficiency of extraction varies widely. In some cases the specific reasons are well known, and in some they are not, but assuming a set efficiency for turning food into energy (and fat) is like the physics joke "first, let's assume a spherical chicken...".)

No I said that. It quite obviously meant that the actual body is more complicated then simple model you have in mind. Effectively, you are using big words to avoid dealing with real world complexity. Scientific approach is to take account of real world complexity, as many factors that influence the outcome as possible etc. Not just throw laws one vaguelly remembers from elementary school.

Lastly, either you want to play manipulative games where you twist words being said to mean what they dont, or you want to discuss actual topic.

I'm honestly not trying to twist words to prove a point. Apparently I didn't understand what you are trying to say.

Calories in v calories out works. It really is that simple. Of course people have different metabolic rates, so you tailor your plan over time to find what works for you. It's an iterative process. If you are aiming for X lbs / week and see Y after a free weeks, then increase or decrease intake.

You brought up rare medical conditions which cause weight gain, typically due to edema or metabolic irregularity. All I said is that those conditions don't apply to the vast majority of people and, even when they do, their bodies aren't storing more energy than they intake and use.

What do you think about the idea that metabolic rates can change, or the proportions of material in the body consumed can change, in response to certain diet and exercise combinations?

I hope no one disputes that thermodynamics exist, but it’s much less certain that every health program receives exactly the same thermodynamic assistance from the body. Keep in mind that the majority of calories burned do not come from active exercise.

It is not just different body. Try to fees on pure sugar+vitamins (exact correct amount of calories) - you will be hungry and disfunctional and possibly gaining weight.

Starving people loose weight. They also develop host of problems, both psychological and physical. And our bodies have mechanisms to force is to eat by instinct to avoid that. When those mechanisms fail, we loose weight while being too tired to work, by gaining weight the first day after diet, by being dumb etc.

But beyond that, sugar is not same as same amount of calories from protein.