Question: how long do you have to fast for intermittent fasting to work?
Answer: The 16/8 method The 16/8 method involves fasting every day for 14–16 hours and restricting your daily eating window to 8–10 hours. Within the eating window, you can fit in two, three, or more meals. This method is also known as the Leangains protocol and was popularized by fitness expert Martin Berkhan.