There is physics supporting calorie in, calorie out. However, there is also pharmacokinetics to consider...if your calories are a sugary solution like juice, Co

There is physics supporting calorie in, calorie out. However, there is also pharmacokinetics to consider...if your calories are a sugary solution like juice, Coke, beer, etc, they will be absorbed into the bloodstream much more quickly, spiking blood sugar and leading to rapid storage in fat cells. Contrast that with the same calories from a lean chicken breast, it's going to be hours until that's fully digested and absorbed, meanwhile it's much more filling and prevents more calories from being eaten. Also because its protein and not sugar, your body metabolizes it differently and it is not going to be stored as efficiently.