OMAD might sound like a modern-day mantra, but it’s an acronym for the “One Meal a Day” diet. If the thought of OMAD has you gripping your hungry stomach, there’s a surprising amount of science backing up intermittent fasting.

We’ll help you understand the ins and outs of OMAD and advise when fasting 23 hours per day might not be the right lifestyle choice for you.

The Basics of OMAD

The OMAD diet involves a 23-hour fast, giving you only a 1-hour window per day when you can eat. 

Supporters of OMAD boast that they don’t have to meal plan three days per week, can eat a massive meal, and feel more energized throughout the day.

There’s no right or wrong time to choose your one-hour eating window—the key is to make it the same one hour every day, when possible. For example, many people prefer eating at dinner when they’re often with family or friends.

We’ll offer scientific-backed explanations for why the OMAD diet might be a healthy option for some people shortly. But for now, the primary takeaway is that it can be an excellent fit for people looking to lose weight, as it prevents excess consumption of calories via mindless snacking during the day.

Steps for Starting Your Fast

The need for willpower comes to most people’s minds when they hear about the OMAD diet. And while that’s true, some people find that eating one meal per day becomes second nature to them over time. 

Meanwhiles, others use OMAD to achieve a specific health or weight loss goal before stopping or modifying it to a less extreme form of intermittent fasting.

Below are the steps we recommend you follow to set yourself up for success when starting OMAD.

Step 1: Start Small

If you’re the type who eats three meals and multiple snacks daily, jumping headfirst into OMAD is a recipe for disaster. Instead, try a modified form of intermittent fasting every other day or every few days.

The goal is to work your way up to intermittent fasting every 16 to 20 hours before you go full-out into your OMAD journey.

Step 2: Incorporate OMAD Into a Weekly Routine

Once you get the hang of shorter intermittent fasting cycles—and no longer mindlessly reach for snacks—try incorporating a 23-hour OMAD fast once or twice per week.

People who already have experience fasting might feel comfortable jumping right to this step. In either case, monitoring how your body responds and your energy levels is crucial for building up your OMAD stamina for the long term.

Step 3: Ensure You’re Eating Enough Calories

It might sound counterintuitive, but it can sometimes be challenging to eat enough calories when following the OMAD diet. The reason is that you can become full quickly by eating a day’s worth of calories in one sitting.

Therefore, although strict calorie counting isn’t technically a part of OMAD, using a calorie calculator can help ensure you’re getting approximately the right amount of calories to sustain you through your next 23-hour fast.

Health Benefits of OMAD

It’s no secret that intermittent fasting in various durations offers health benefits. Below are some of the most notable positive changes you might encounter from adopting an OMAD lifestyle.

1. Reduces Chance of Disease

Intermittent fasting forces your cells into hormesis, mild stress that causes them to become more resilient. Hormesis might be a new word to you, but researchers have noted its positive impacts for years.

Studies in animals show that stress from temporary dietary restrictions can prevent or reduce the impact of stroke, allergies, cancer, and Alzheimer’s.

2. Increases Metabolism

You’ve likely heard that yo-yo dieting can slow down your metabolism, but the reason for this is that it often involves eating fewer calories than your body needs every day to function. In contrast, when your body goes into a fasting state, it temporarily increases your metabolism by breaking down fat.

So, by eating according to OMAD, you can expect up to a 14% boost in metabolism. The effect doesn’t last more than 48 hours before it’ll have the opposite effect and slow your metabolism, though.

3. Improved Heart Health

Several studies show that intermittent fasting is beneficial for the heart. A leading theory for this is that it increases a type of protein that helps reduce inflammation. 

By embarking on an OMAD lifestyle, you may notice lower blood pressure and cholesterol. Your resting heart rate may also go down, a sign that your heart doesn’t have to work as hard to pump blood throughout your body.  

4. Slows Aging

Autophagy might be another word you’re unfamiliar with, but if you’re hoping to ward off wrinkles, it’s important. The body is full of damaged cells, and autophagy is a process that helps clean them out, along with removing damaged organelles and aggregated proteins.

The bottom line for all this jargon is that autophagy helps eliminate the waste and toxins that contribute to aging.  

Non-health Benefits of OMAD

Although many people choose to follow OMAD for health reasons, below are a couple of situations that also make this diet attractive for some.

Less Time Consuming

Let’s face it—eating is fun for most of us, but it takes time to cook and consume a meal. Even if you eat out, there’s still time involved in thinking about what you want to eat and going through the process of getting it.

With OMAD, you only have to plan one meal per day. It’s an important one, of course—you must ensure you get all your macro and micronutrients in one sitting. But many people on the go find they enjoy having to only think about food once daily.


Most people following an OMAD diet eat fewer calories, directly equating to more money in your pocket. 

For example, you’ll automatically have to turn down a stop at the drive-through for some fries or the ice cream you eat with your kids on (every) summer night whenever the temptation of food falls outside of your one-hour eating window.

Tips for Sticking With OMAD

Starting OMAD can feel challenging to the uninitiated, but there are items you can do to make it easier to stick with this diet. They include:

  • Avoid processed foods
  • Reduce food temptations
  • Increase protein and fat intake
  • Consider eating in the middle of the day

If you gorge on sugary foods during your OMAD diet, they’ll give you a massive blood sugar spike before leaving you hungry and craving more food shortly after. So, incorporating high-quality protein and fat into your diet will keep you satiated longer.

Reducing temptation is another helpful strategy for improving your chances of not breaking your fast before the 23-period cycle ends. So, keep food out of sight and make it difficult for you to access snacks (such as having to drive to the grocery store) should hunger strike.

Finally, although many people enjoy breaking their OMAD fast at night, eating in the middle of the day can help if you’re struggling with hunger.

When OMAD Might Be a Bad Choice

You should always speak with your doctor before starting a diet as extreme as OMAD. Some situations that could make OMAD a poor choice include:

  • High stress levels
  • A naturally fast metabolism
  • Intense, frequent exercise

If you’re a perfectionist, we encourage you to practice a flexible mindset if you embark on OMAD. Research shows intermittent fasting benefits at much lower fasting timeframes than 23 hours. 

So, if you can’t stand your hunger after 20 hours, give yourself grace and eat then. Listening to your body is crucial. Therefore, if you feel you have obsessive tendencies when following a diet, OMAD might not be the right fit for you.

FAQs About Fasting

Do you still have questions about OMAD and fasting? Below are answers to common inquiries.

What do you eat on OMAD?

You can eat any foods you want on OMAD if you only eat them within a one-hour window every 24 hours. While some people opt for junk food, we encourage you to consume most of your calories from healthy foods.

How many calories should I eat on OMAD?

The number of calories you should eat on OMAD depends on your weight loss goals. If you’re trying to lose weight, you should eat at a calorie deficit. Otherwise, most adults need 1,600 to 2,400 calories per day for weight maintenance.

Can I drink coffee on OMAD?

Yes, you can drink coffee and any beverage without calories while following OMAD. Black coffee, tea, and water are the most popular drinks during your fast.

Is OMAD Right for You?

Despite OMAD’s many appealing potential benefits, it’s not the right lifestyle choice for everyone. So, we encourage you to work your way towards following an OMAD lifestyle gradually. 

If you feel ill at any time or it’s not right for you, perhaps choosing a more moderate intermittent fasting diet would be better. Regardless of your approach, it’s best to speak with your doctor before making any dietary changes.