So if I consume 3,000 calories a day entirely from fat, and only expend 1,500 calories a day via metabolic processes and physical activity, I won't gain weight? And, if I eat 1,500 calories a day from only sugar and starch, but burn off 3,000 calories a day, I won't lose weight because all calories consumed came from carbs? Is that what you're claiming?
That's what it sounds like. If so, you need to rethink what you've written.
It takes quite a while to process the fat into calories, some of it might pass right through.
The sugar is instantly converted to calories...or stored as fat.