Hunger is the initial side effect of IF. However, this is only temporary as your body are adapting to a new form of dieting. Personally, it took me a week for my body to adapt. Here’s a tip to ease into IF. On the first week of applying IF, eat your calories maintenance or TDEE to ease your body into getting used to the 8-hours eating window. For example, with reference to “Part II: Calories” above, I will eat my TDEE of 2,425 on the first week of IF, after which, I will drop it by down to 2,183 calories at 10% caloric deficit in the second week.