16/8 intermittent fasting what's it? The intermittent fasting fashion known as16/8 entails confining your diurnal mess and libation consumption to a window of 8 hours. For the coming sixteen hours, you refrain from eating, but you're still permitted to drink water and other calorie-free liquids, similar as black tea or coffee. This cycle can be repeated as frequently as you'd like, ranging from formerly or doubly a week to every day, depending on your schedule.