It's not "basic physics."

You're implying that "calories in" are all absorbed equally. We poop. Literally. Calories go out that are never absorbed. Every body does this differently. Is that physics too?

Also: some people get calories from certain foods that other people don't get calories from. Is that physics?

Can you lose weight from a calorie restriction diet? Of course! But don't claim that it's the only answer. It's not. The human body deserves more respect than that.