Intermittent fasting (IF) involves not eating (aka fasting) for part of each day or a few times a week. One common example of this is to eat only during an eight-hour window in a day and fast for the other 16. When your body doesn't have a constant energy source from the food you eat, it allows your body to utilize the fat stores it already has, helping you lose belly fat.
Ferrari and Luiza Petre, MD, a weight-loss specialist and board-certified cardiologist, told POPSUGAR that intermittent fasting raises growth hormone levels and lowers insulin levels, both of which help burn more fat. "Insulin decreases when you fast, and lower levels of insulin results in burning more fat," Ferrari added.
Eating in a shortened window not only reduces hunger (it's true!), but since you're not eating for long periods of time, there are also fewer opportunities to consume calories, which is why IF helps people eat fewer calories effortlessly.