How to Eat Just One Meal a Day on Keto (OMAD)

Find out why so many people are eating OMAD on keto!

In the keto community, it’s fairly common to hear people talk about incorporating intermittent fasting (IF) into their way of eating. Combining IF with keto can increase the health benefits of a ketogenic diet, accelerate weight loss, and nudge you off a stubborn plateau when your progress has stalled.

Usually, someone who is using intermittent fasting will abstain from eating for most of the day and restrict their eating to a set window of time. A person who is doing 16:8 IF, for example, fasts for 16 hours and does all of their eating for the day during an 8-hour window of time.

One Meal a Day (OMAD) is a form of IF that narrows your eating window to – you guessed it – just one meal a day.

You could think of OMAD as 23:1 intermittent fasting, although there’s no set amount of time you need to spend eating that one meal.

Fans of eating OMAD on keto love this approach because it propels their body into a state of ketosis faster than simply eating keto or even traditional IF.

But is OMAD a safe, healthy, and sustainable way of eating?

What are the benefits of eating OMAD on keto?

Doctors who prescribe a ketogenic diet and intermittent fasting often use OMAD as a tool to help overcome weight loss plateaus. When a patient is already eating keto but isn’t losing weight, OMAD can help to move the needle on a stubborn scale.

Clinically speaking, eating OMAD on keto may help to reduce blood sugar, control diabetes, and overcome metabolic disease. Although there hasn’t been much research done specifically on OMAD, we do know that extending a fasting window can help to improve these health conditions, so eating OMAD could result in even better outcomes than shorter fasts.

While some people find it difficult to exercise while fasting, research has actually shown that exercising on an empty stomach is safe and effective for weight loss. There’s a prevailing belief that it might work even better for weight loss than “fed exercise,” but this has yet to be proven.

If you’re only eating OMAD, then you’ll have a larger window of time throughout the day when you can reap the added benefits of exercising during your fast.

Many people who experience success by eating OMAD on keto find that they also benefit from a firm eating schedule that restricts their snacking. If snacking is your downfall, this way of eating makes it virtually impossible!

You may also discover that it’s nice to spend less time planning, food shopping, meal prepping, and doing the dishes. Imagine only having to clean up the kitchen once per day! Of course, this will only work if everyone else in your household is eating OMAD too. 😉

What are the challenges associated with eating OMAD on keto?

While many people thrive when eating one meal a day, this approach is highly individual and it’s not ideal for everyone. Eating large quantities of food after a period of restriction could trigger eating disorders in anyone susceptible to these conditions. If you have a history of an eating disorder or if you think you could be triggered by this cycle of eating, you shouldn’t try OMAD without first discussing it with a trusted health care professional.

Another pitfall of eating OMAD is that it can be challenging to get an entire day’s worth of nutrition in one sitting. This leads to a reduced caloric intake, which is why OMAD is so effective for weight loss… at first. Research has shown that chronic calorie restriction over time can actually lead to a slower resting metabolic rate, making continued weight loss more difficult to achieve and maintain. For this reason, you may want to consider implementing OMAD for limited periods of time only.

Aside from naturally restricting your caloric intake, eating OMAD can also make it difficult to get all the macronutrients you need. Since protein causes feelings of fullness and satiation, it can be really hard to eat an entire day’s worth of it in one sitting. Depending on your body type and your health goals, you may need to eat 100g of protein or more per day. If the idea of eating that much protein in one sitting seems intimidating to you, then you may struggle with eating OMAD on keto.

Eating OMAD also forces you to consume all of your day’s carbohydrates within a short window of time. While this won’t be a problem for everyone, eating 20 grams of carbs all at once could be enough to knock a person out of ketosis if they’re highly insulin resistant. Some people also report diarrhea, bloating, acid reflux, and other forms of gastrointestinal discomfort after eating their meal.

Finally, if you need to take prescription medication with food more than once a day, eating OMAD may not be possible for you. You may wish to consult your health care professional in this situation to see if there is another medicine you can take or a different medication schedule to try. But ultimately, there are some people who will not be able to attempt OMAD due to their prescription medications.

What is the best way to eat OMAD on keto?

Some people eat OMAD every day for a set period of time, while others use it on an intermittent schedule over a longer stretch of time.

For example, many folks in the keto community find that eating OMAD a few times a week (on non-consecutive days) is the most effective method for them over the long term. They may start out by eating OMAD every day, but then settle into this intermittent schedule when they’re ready to move into a “maintenance” phase after achieving their health goals.

Most people eating OMAD find that daytime meals work best for them because eating during the day seems to have the most favorable effect on their sleep/wake cycle. One study suggests that finishing your meal by 4 PM is ideal.

Eating a large meal in the evening can disrupt your circadian rhythm and make it harder for you to fall asleep at night. Animal studies have also shown that eating during the day (rather than at night) promotes the development of a more anti-inflammatory gut microbiome.

Whether your OMAD is breakfast, lunch, or an early dinner, it’s definitely not a license to eat whatever you want. In fact, since you’re only eating one meal a day, the nutritional profile of your meal is more important than ever!

No matter what time of day you eat, your OMAD should be a scaled-up version of a typical keto meal that you would eat on any other day. Even if you don’t normally track your macros, it’s a good idea to keep an eye on these metrics to ensure you’re consuming everything you need to maintain your health. You can try a macro calculator and tracking app like Carb Manager for help monitoring your meals!

No matter what your approach to eating OMAD, it’s crucial to stay hydrated throughout the day, especially during your fasting window. It may be a good idea to supplement your diet with electrolytes during this time to prevent headaches and keep you feeling your best until your next meal.

Should you try eating OMAD on keto?

While many people find that they’re drawn to eating OMAD for all of the benefits mentioned above, some also find eating just one meal a day often makes sense for them if they’re already living the keto life.

Once your body is fully fat-adapted, you will feel satiated for longer stretches of time and you may not be hungry at traditional meal times throughout the day. This is a big reason why eating just one nourishing, nutrient-dense meal per day can seem very appealing to so many people eating keto.

Keep in mind that you should always consult with your health care provider before making any major changes to your diet. Although many people thrive while eating OMAD, others are more susceptible to side effects. Feeling a little hungry or less energetic than usual is to be expected, but you should not feel very unwell, extremely fatigued, dizzy, nauseated, or experience any other severe side effects.

At this point in time, there haven’t been any well-controlled clinical trials examining the safety and effectiveness of eating OMAD, but your health care provider should be able to offer you guidance as to whether this way of eating would be safe for you to try.

No matter where you are on your keto journey or which approach you choose, we’re here to support you along the way!

Up next: We shut down 5 of the most pervasive keto myths!