That is problem with CICO proponents start with scientific terms. But it always ends up with magic what does or does not count based and whatever the argument they are in. CICO models doesn't state anything they claim, but it in the end it's argument into nothing. Because human cells does not use calories it uses ATP through the kerb cycle. That whole process so bizarre complex, and then also based on so many confounded factors, that CICO is just too simplistic and it's almost impossible to lose weight and keep it off according to the model.
Link to study about how the biggest losers contestants are doing after the show. Hint not well...
https://www.health.harvard.edu/diet-and-weight-loss/lessons-...