OMAD Fasting Timer

One meal a day usually means a 23-hour fast and a 1-hour eating window. Set a 24-hour goal and stop the timer when you eat — or use 16:8 while building up to OMAD.

How to use this

  1. Choose water-only or assisted fasting, pick your goal hours, and set your profile for personalized guidance.
  2. Tap Start fast when you finish your last bite. When you reach your goal, we show how to break the fast with meal ideas.
  3. Follow doctor-sourced tips for electrolytes, cycle timing, and when to break your fast safely.
Fasting type
Goal duration

Optional: Dr. Boz Ratio (glucose ÷ ketones)

Track metabolic progress during your fast. Target under 80 for ketosis; under 40 for deeper benefits (Dr. Boz).

Breaking an extended fast (19–35h)

After a gut-reset or autophagy fast, your digestive system is resting. Dr. Mindy recommends protein, fat, and fiber — but in a moderate portion, not a feast.

How to break your fast

  1. 1Optional first: warm bouillon or bone broth (Dr. Westman) — especially after water-only fasts.
  2. 2First meal: protein-forward and low carb. Aim for ~15–25g protein with healthy fat.
  3. 3Include gentle fiber: leafy greens, cucumber, or broccoli — not a huge raw salad right away.
  4. 4Eat slowly and stop at comfortable fullness — your hunger signals may be sharper than usual.
  5. 5Resume your normal low-carb eating window. Skip dessert and processed carbs for this first meal.

What to avoid

  • • Breaking your fast with fruit juice, smoothies with banana, or sugary yogurt.
  • • Large portions — treat this like two small meals 30 minutes apart if needed.
  • • Heavy cream coffee with sugar — black coffee or tea is fine if you already tolerate it.

Expert tips

  • Dr. Mindy Pelz: This is her weekly "gut reset" break — quality protein, healthy fat, and fiber stabilize blood sugar after autophagy.
  • Dr. Eric Westman: Salt your food normally when you eat. If you feel lightheaded, bouillon before your meal helps.
  • Dr. Boz: Check your Dr. Boz Ratio after eating — a gentle protein meal should keep ketosis reachable without a glucose spike.

Not medical advice. Guidance synthesizes public teachings from Dr. Mindy Pelz, Dr. Eric Westman, and Dr. Boz. Talk to your doctor before fasting — especially on diabetes, blood pressure, or kidney medications.

Fasting timer

Ready to start

00:00:00

Set your goal and tap Start fast. Your timer persists if you close the tab.

Related guides

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Frequently asked questions

What is OMAD?

One meal a day — you eat a single substantial meal daily and fast the other ~23 hours. It is a form of extended intermittent fasting.

Is OMAD safe?

Not for everyone. Avoid OMAD if pregnant, underweight, or on diabetes medications without medical supervision. Start with 16:8 before jumping to OMAD.

What should my one meal include?

Protein, healthy fats, and low-starch vegetables — enough calories to meet your needs in one sitting. See our break-fast guide and recipes.

Other calculators

Metabolic Low Carb Calculator · https://metaboliclowcarb.com