> But it's always true that if you manage to eat fewer calories than your body needs each day you will lose weight.
No, not necessarily. Several studies have shown that different people can get different amounts of energy out of the same food, depending amongst others on their gut micro biome, though stress also seems to play a role. It’s never going to be that simple.
> the laws of thermodynamics won't fail
Conventional thermodynamics don’t work when you consider a full human, which is a very out-of-equilibrium and not-isolated system. Conservation of energy does not tell you anything about the efficiency of the energy extraction process.
No, not necessarily. Several studies have shown that different people can get different amounts of energy out of the same food, depending amongst others on their gut micro biome, though stress also seems to play a role. It’s never going to be that simple.
> the laws of thermodynamics won't fail
Conventional thermodynamics don’t work when you consider a full human, which is a very out-of-equilibrium and not-isolated system. Conservation of energy does not tell you anything about the efficiency of the energy extraction process.