Yup sleep time counts! And you can drink water and coffee and other zero calories drinks. Some say you should avoid zero-calorie sweeteners. So 4 hours no eat

Yup sleep time counts! And you can drink water and coffee and other zero calories drinks. Some say you should avoid zero-calorie sweeteners. So 4 hours no eating before sleep, 8hrs sleep & 4hrs after sleep is a 16 hour / 8 hour IF fast. Basically don't snack after dinner and skip breakfast. You can do longer fasts for different reasons, but that is the basic one.