You presumably mean intensity as impact is not relevant. If you're burning more fat, while your carbohydrate intake is being converted to fat instead of burned then why would the net result not be the same? Typically high intensity exercise is done for a shorter period, so the resulting energy consumption is the same. In general the amount of fat being burned is inversely proportional to the availability of carbohydrates to burn. Anyway eating more than you're using always matters.And energy out comparisons are also meaningless. Low impact exercise will tend to burn fat, while high impact will not.
Insulin spike is irrelevant, unless you then proceed to eat more because you think you're hungry.Do you honestly believe that a steak and salad is exactly equivalent in effect to the same kilojoule quantity of chips and coke? Hint: one of these meals will cause your insulin to spike, the other one won't.