OMAD, One Meal a Day, is close to what it sounds like. You eat once, typically within a single hour, and fast the rest of the day. In fasting notation it's roughly 23:1. There's an appealing simplicity to it: no windows to track, no second meal to plan. Just one meal, done with intention.
| Fasting window | ~23 hours |
|---|---|
| Eating window | ~1 hour, one meal |
| Frequency | Daily, or a few days a week |
| Difficulty | Advanced |
| Best for | Experienced fasters who value simplicity |
| Consider a doctor's input if | You are new to fasting, pregnant, underweight, or managing blood sugar |
What OMAD is
With OMAD, all daily nutrition arrives in one sitting. That's both its appeal and its difficulty: there's little to think about for 23 hours, but the single meal needs to cover a full day of protein, micronutrients, and energy, which takes more planning than it sounds.
Why people choose it
Some like the simplicity: one meal removes a lot of daily decisions. Others find their appetite settles into a predictable rhythm. Done thoughtfully, OMAD can feel calm and sustainable for some people. Done carelessly, it can tip into under-eating or an unplanned binge.
A common OMAD mistake is treating the one meal as a small meal. It's meant to cover a full day of protein, vegetables, and energy on one (larger) plate. Under-eating here can show up in sleep, mood, and muscle over time.
A sample day
- All day - Water, black coffee, unsweetened tea. Electrolytes as needed.
- 6:00pm - Sit down to one large, complete meal. Eat slowly, over 45 to 60 minutes.
- 7:00pm - Window closes; the next fast begins.
Building the one meal
A single plate is generally built to cover a full day of needs: a large protein serving, plenty of vegetables, quality carbohydrates, and healthy fats. Some people split it into a starter and a main to make the volume more manageable. Protein tends to be the priority, to help protect lean mass.
Composing a complete OMAD plate
A full day of nutrition in one sitting
Large protein serving
Leading with 40 to 50g of protein helps protect lean mass.
Vegetables, generous
Volume, fibre, and micronutrients in one go.
Yogurt & fruit
A protein-rich finish that's gentler on blood sugar.
Who it suits
Best for
- Seasoned fasters who want maximum simplicity
- People with steady, predictable appetites
- Those whose schedule makes one meal easiest
Watch-outs
- Beginners (building up through 16:8 and 18:6 first is common)
- Anyone prone to bingeing or food preoccupation
- Highly active people with large energy needs
- People managing diabetes or blood-sugar issues
Doing it safely
OMAD is often considered the deep end of fasting protocols. Reaching it gradually, keeping the one meal genuinely complete, and considering electrolytes through the longer fast are common practices. Tracking protein deliberately and watching energy, sleep, and mood can help. Many people don't do OMAD daily; a few days a week can capture much of the appeal with less strain. If it starts to feel like restriction rather than rhythm, widening the window is a reasonable choice.
Frequently asked questions
What does OMAD mean?
Is OMAD safe?
How much should I eat on OMAD?
Do I have to do OMAD every day?
References & further reading
- Stote KS, et al. "A controlled trial of reduced meal frequency without caloric restriction in healthy adults." AJCN, 2007.
- Patterson RE, Sears DD. "Metabolic Effects of Intermittent Fasting." Annual Review of Nutrition, 2017.
- Templeman I, et al. "Fasting, energy restriction, and metabolic health." Science Translational Medicine, 2021.
This guide is for general educational purposes and is not medical advice. Intermittent fasting is not appropriate for everyone, including people who are pregnant or breastfeeding, those with a history of disordered eating, or anyone managing diabetes or other medical conditions. Speak with a qualified clinician before making significant changes to how you eat.
