What is the relationship between calories and energy? Peat has mentioned that after taking thyroid his caloric intake halved, and I've never been able to understand that. Shouldn't thyroid increase caloric requirement?
Or, to put as a practical example: if two individuals ate either 2000kcal or 3000kcal, if all other factors were equal and neither were gaining weight, would the latter be in a better state of health, energetically speaking, than the former?
When thyroid is not working well, we "waste" glucose converting it in lactic acid and fat. With thyroid, most glucose is converted to ATP and we can get by on a lot less. The extreme illustration of this is in cancer where the tumor just cannot get enough energy through inefficient glycolysis and ends up consuming the host.