

The big difference is the effect of a calorie for each person differs. How the body chooses to burn a calorie differs. If person A reduces their diet by 3000 calories in a week they might lose a pound. Person B might not. CICO is literally thermodynamics, you’re very right. How our bodies react to thermodynamics varies quite a bit.








What I’m talking about but maybe didn’t do a very good job of explaining is metabolic adaptation. It can take months before your body adjusts, before you figure out what calorie deficit is needed and it varies wildly from person to person. Our brains can burn calories to be more creative or slow down to preserve ideal body weight. Which can negate a wide amount of calorie usage. https://www.sydney.edu.au/news-opinion/news/2023/07/05/its-time-to-bust-the-calories-in-calories-out-weight-loss-myth.html