Have your 20 calories. In my experience exercise is extremely beneficial so whatever extra 20 calories it will be burned up.I have read the purists and tried the super clean version, but from experience, ketosis is more important than being “clean”. As long as you are not eating a piece of candy ( ie you’re having cream in coffee ) it’s fine. Especially if you exercise.The goal of ANY diet is consistency… something you can maintain that achieves results. The pure fast is fine but it didn’t help me lose weight particularly fast so I added more fats and it helped a lot.