If you are used to eating carbs, you are hungry every two hours so fasting sounds impossible. Going low carb first makes this really easy. People need to be more open minded and try new things. I do alt day fasting, I save all my difficult mental work for fasting days. Absolutely love it. But I really eat on eating days. Dr Fung also says eating is like peeing: once you start you don't want to stop until you're done. I cannot imagine what superpower you need to pee a bit and then pee later. It's just like eating 100 calories and then stopping even though you are now even hungrier. Impossible.