There's a strong biological push to overeat following fasting periods as your appetite hormones and hunger center in your brain go into overdrive when you are deprived of food. This raises the risk of engaging in unhealthy eating habits during non-fasting times. Research also suggests that calorie-restricted diets may lead to a slowed metabolism and increased appetite. To prevent overeating, stay hydrated, have your first meal prepped, start off your eating window with veggies, eat slowly, eat enough, and make your last meal balanced and filling.