OMAD Fasting Timer

One Meal A Day (OMAD) compresses eating into a single hour — effectively a ~23-hour daily fast. It is advanced intermittent fasting, not a starting protocol. Use this timer only after shorter IF windows feel easy and medically appropriate.

How to use this

  1. Choose water-only or assisted fasting and pick your goal hours.
  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. Stage labels mark educational time windows only — they do not prove biological processes occurred.
Fasting type
Goal duration

Optional: Dr. Boz Ratio (glucose ÷ ketones)

Formula: glucose (mg/dL) ÷ ketones (mmol/L). Interpretations are educational only — not diagnostic targets. See our ratio guide for limitations.

Breaking an extended fast (19–35h)

After a longer fast, your digestive system may need a gentle restart. Start with protein, fat, and fiber in a moderate portion — not a feast.

How to break your fast

  1. 1Optional first: warm bouillon or bone broth — 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.

Tips

  • A moderate protein-and-fat meal with gentle fiber is a common refeed pattern after longer fasts.
  • If you feel lightheaded before eating, a small amount of broth or water may help — seek care if symptoms persist.
  • Optional glucose/ketone tracking after eating is for personal observation only; it is not a diagnostic test.

Suggested break-fast meals

All recipes

Read the full break-fast guide →

Not medical advice. This timer tracks clock time only. Talk to your doctor before fasting — especially on diabetes, blood pressure, or kidney medications. Do not adjust medication on your own.

Fasting timer

Ready to start

00:00:00

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

Making one meal nutritionally complete

One meal must cover protein, vegetables, healthy fats, and micronutrients for the whole day. Undereating protein on OMAD can cost muscle mass over time — review protein on keto.

See best first meal after fasting for composition tips, then scale that plate up carefully rather than inhaling junk in sixty minutes.

OMAD and blood sugar medications

A single large meal plus all-day fasting shifts glucose patterns dramatically. Medical supervision is essential on insulin or sulfonylureas — do not adjust medication on your own. Read fasting on diabetes medications.

Build up, do not jump

Prove 16:8 and 18:6 first with the intermittent fasting timer. OMAD is optional intensity, not a badge. Many metabolic goals are reachable without living on one plate forever.

Related guides

Fasting

Best First Meal After Fasting — Low-Carb Ideas

Protein-forward break-fast meals for 16-hour IF and 24-hour fasts. Recipe ideas with net carb counts for keto and insulin resistance.

8 min read

Fasting clock →

Fasting

16:8 vs 18:6 Intermittent Fasting — Which Is Right for You?

Compare 16-hour and 18-hour eating windows, the limits of current evidence, and situations that require clinical advice.

9 min read

IF timer →

Fasting

Electrolytes During Fasting — Sodium, Potassium & Magnesium

What sodium, potassium, and magnesium do, why symptoms are nonspecific, and when supplements can be unsafe.

11 min read

Extended fasting clock →

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. Good OMAD plates include sheet pan chicken with cabbage or a salmon avocado poke bowl (see Recipes). Pair with our break-fast guide for refeed timing.

Other calculators

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