Question: how long do you have to fast before you start losing weight?
Answer: In this review, intermittent fasting was found to reduce body weight by 3-8% over a period of 3-24 weeks (2). When examining the rate of weight loss, people lost about 0.55 pounds (0.25 kg) per week with intermittent fasting, but 1.65 pounds (0.75 kg) per week with alternate-day fasting (2).