Two 120 pound people - one being a marathon runner and one being sedentary run for 1 mile. CICO “science” says they burn the same amount of calories (physics 101 - weight over distance). It is not even close, the marathon runner is so adapted and efficient that they cannot burn nearly the calories of the sedentary person.
2 people of identical physical structure eat 2,500 calories of cheese covered butter fried ribeye. The two people are hormonally completely different with the first having regularly low insulin, good sleep and low stress but the second is has high insulin, sleeps 4 or 5 hours a night and is in the middle of an ugly divorce. Both continue to undertake the same activities. CICO “science” says they will store the same amount of fat but, it is obvious that the person with the better hormone profile will store much less.
CICO “science” applies to cars - put a gallon of gas in an empty car, it will travel a certain distance and then stop. Add a bunch of gas and run it a few thousand miles more until it is empty, add another gallon and again, it will go the same distance as the first time. It cannot “adapt” like people can to use fuel more or less efficiently.
“science-denying stuff” could be thought of as what keto is all about - add calories to lose weight - crazy right? But, it turns out to be healthier (considering everyone’s better blood numbers) and to have better longevity (people commonly seem to bounce on calorie restriction but there are some very long term happy ketoers on this site).