The 5:2 diet, explained

Not all fasting is a daily eating window. The 5:2 approach fasts by the week instead — five normal days, two very light ones. Here's how it works.

The Kairo Guide · 4 min read

How 5:2 works

On the 5:2 diet you eat normally five days a week and cut way back on two non-consecutive days — traditionally to about 500 calories for women and 600 for men on those "fasting" days. It's a form of intermittent fasting that restricts by the week rather than every day, which some people find far easier to fit into real life.

What a fasting day looks like

With only 500–600 calories to spend, protein and volume matter most: eggs, Greek yogurt, lean protein, and lots of vegetables keep you full. Many people split it into a small breakfast and dinner, or a single larger meal. Black coffee, tea, and water are your friends on these days.

Pros and cons

• Pro: five days feel completely normal — no daily window to police.
• Pro: only two days a week require real discipline.
• Con: those two days can feel genuinely tough, especially at first.
• Con: it's easy to overeat on the five "normal" days and cancel out the deficit.

5:2 vs daily 16:8 — which is better?

Neither is superior for weight loss; they're two routes to the same weekly deficit. Choose by temperament: if you'd rather have a couple of hard days and forget about it the rest of the week, 5:2 fits. If you'd rather a small daily rule and no "bad" days, daily 16:8 fits. Some people even combine a gentle daily window with one lighter day.

General information only, not medical advice. Consult a healthcare professional before starting any fasting routine, especially if you are pregnant, under 18, have a medical condition, or a history of disordered eating.