There is no > fallacy of calories in/out and it has everything to do with thermodynamics. This is exemplified in your very own example: fidgeting more means a

There is no > fallacy of calories in/out and it has everything to do with thermodynamics. This is exemplified in your very own example: fidgeting more means a higher expenditure of energy. Chemical energy doesn't magically disappear. While metabolic regulation is certainly a complex subject it is simply wrong to categorically state that thermodynamics is somehow obviated.