That is incorrect. Many things can cause the human body to burn fewer calories than height, weight, and activity would suggest, and one of the easiest ways to d

That is incorrect. Many things can cause the human body to burn fewer calories than height, weight, and activity would suggest, and one of the easiest ways to determine if someone is affected by one of those metabolic dysregulations is to take their temperature. If their temperature isn't 98.6 degrees Fahrenheit or very close to it, they are metabolically compromised (note, of course, that people will practically never have a resting body temperature of greater than 98.6) I had a full dexa scan and calorimetric exam done and my body was burning approximately 300 calories a day under what it was supposed to. My resting body temperature was 97.3. If I ate what my TDEE should have been I would have been putting on half a pound a week or more. Eating more and exercising to rebuild muscle lost to over dieting has corrected that issue. But saying that it doesn't exist is completely wrong. The math is still "calories in, calories out" but you can't assume that "calories out" is static and inflexible. There are many variables at play in the human body.