Because a little bit of oil adds a lot of calories.

(And is the evidence about coconut oil conclusive? Last I heard it may or may not be good.)

A tablespoon of olive oil is 120 calories. Unless you are completely sedentary, or are using 15tbsp a day, it’s a negligible amount.

> Unless you are completely sedentary,

This is Hacker News. Of course he's completely sedentary

120 extra calories a day is an extra 12 pounds a year. Combine that with your metabolism slowing down as you age and as the years pass you might find yourself expanding.

Also, the amount of oil you avoid by moving from deep frying to air frying, depending on portion sizes, can be much more than a tablespoon.

(Obviously, metabolism is more complex than this. I'm discounting the effects of adding fat on satiety, absorption rates, etc.)