Intermittent fasting (IF) cycles between eating and fasting periods rather than specifying which foods to eat. The 16:8 method limits eating to an 8-hour window; 5:2 restricts calories on two non-consecutive days. IF often works for weight loss simply because a shorter window makes it easier to stay in a calorie deficit. It is not magic — total weekly calories still matter. People who are pregnant, have a history of disordered eating, or take certain medications should avoid IF or consult a clinician first.
Key facts:
- 16:8 = 16 hrs fasting, 8 hr eating
- 5:2 = 2 low-calorie days per week
- Works mainly via calorie deficit
- Not for pregnancy or eating-disorder history