What is intermittent fasting? Intermittent fasting (IF) is an eating pattern that cycles between periods of fasting and eating. It does not restrict what you eat, but rather when you eat. Common protocols like 16:8 (16 hours fasting, 8 hours eating) leverage the body's natural fasting state to improve insulin sensitivity, promote fat oxidation, and trigger cellular autophagy — all without complex calorie counting.
| Protocol | Fast / Eat | Difficulty | Best For |
|---|---|---|---|
| 14:10 | 14h / 10h | Beginner | IF beginners, easy to maintain |
| 16:8 | 16h / 8h | Easy | Weight loss, general metabolic health, most popular |
| 18:6 | 18h / 6h | Moderate | Accelerated fat loss, improved insulin sensitivity |
| 20:4 | 20h / 4h | Hard | Advanced users, Warrior Diet adherents |
| OMAD | 23h / 1h | Very Hard | Maximum simplicity, rapid weight loss |
| 5:2 | 2 low-cal days | Moderate | Flexibility, long-term sustainability |
Extended fasting periods deplete glycogen stores and force the body to shift toward fat oxidation. Over time, this trains your metabolism to switch efficiently between burning glucose and fat — a state called metabolic flexibility, which is associated with improved energy, body composition, and athletic performance.
Periods without food allow insulin levels to drop, which improves cellular insulin sensitivity. Lower baseline insulin promotes fat burning and reduces the risk of type 2 diabetes. Studies show consistent IF can reduce fasting insulin by 20–31% and fasting blood glucose by 3–6%.
During extended fasting (typically 16+ hours), the body initiates autophagy — a cellular "self-cleaning" process where damaged organelles and misfolded proteins are broken down and recycled. This process is linked to longevity, reduced cancer risk, and protection against neurodegenerative diseases.
Many IF practitioners report improved mental clarity during fasting periods. This is partly attributed to the production of ketones (an alternative brain fuel), reduced neuroinflammation, and elevated brain-derived neurotrophic factor (BDNF), which supports learning and memory.
Knowing your schedule is just the start. The FitScanned app helps you log meals, track your eating window, and scan food with AI to ensure you break your fast with the right foods.