Fat balance is a much simpler equation than you think. You can think of fat cells on your body as tiny storage tanks for fuel (from food). When you eat and digest food, you store more fuel, and when you’re not eating, you’re using that fuel to the extent of your activity level. The more you push in the direction of usage, the more stored fuel you will use and your fat cells will naturally shrink (this is what most people are looking for when trying to improve their shape and add “cuts” – muscle already has shape, it’s just covered under fat reserves).
Thinking in terms of how many calories you’re burning during a workout or how many you’re eating in a day is too acute. You need to think of the longer term balance of fuel stored vs. fuel used. You get more “mileage” from higher calorie foods and that’s why it’s difficult (but not impossible) to lose fat on mostly high-calorie “junk” treats. So it’s okay and it actually makes sense to go very low-calorie (if you can tolerate it) for a few days in anticipation of a day or meal when you will be taking in more calories.
And while exercise uses up additional fuel, you still need to think of the other 23 hours in a day.