Except that energy burned is not by any means a 1:1 correlation with exercised performed. We are inefficient machines, and our efficiency characteristics vary wildly in ways we don't fully understand.
Two people consuming the same quantity of energy and exerting the same number of joules on exercise equipment do not see identical or even necessarily related physiological effects. There are many, many factors - other nutrients, genetics, timing, the distribution of work over time (short intense exercise vs. long less intense exercise, etc.) and they all matter.
There are skinny people who have never been inside a gym. There are fat people who work harder than you. Obviously you can still influence your outcomes, but "energy out >= energy in" is a gross oversimplification.
Two people consuming the same quantity of energy and exerting the same number of joules on exercise equipment do not see identical or even necessarily related physiological effects. There are many, many factors - other nutrients, genetics, timing, the distribution of work over time (short intense exercise vs. long less intense exercise, etc.) and they all matter.
There are skinny people who have never been inside a gym. There are fat people who work harder than you. Obviously you can still influence your outcomes, but "energy out >= energy in" is a gross oversimplification.