Intermittent fasting (IF) is an eating pattern that cycles between periods of fasting and eating. It is not a diet — it specifies when to eat, not what to eat.

Common protocols:

• 16:8 — 16-hour fast, 8-hour eating window (most popular)
• 5:2 — Eat normally 5 days, restrict to ~500 calories on 2 non-consecutive days
• OMAD — One meal a day (extreme 23:1 fast)
• Alternate day fasting — Fast every other day

Proposed mechanisms:

• Reduces overall calorie intake (primary driver)
• Improves insulin sensitivity
• Triggers autophagy — cellular cleanup process
• May improve metabolic health markers

Key insight: Research suggests IF is effective for weight loss but not superior to continuous calorie restriction when calories are matched.

Reference:

Wikipedia: Intermittent fasting

https://en.wikipedia.org/wiki/Intermittent_fasting