The one meal a day (OMAD) diet is a friendly way of eating that involves having just one meal each day and fasting for the rest of the time. It’s like picking either breakfast, lunch, or dinner and eating all the necessary nutrients for the entire day in that one meal. After that, you fast for approximately 23 hours until your next meal.
Eating one meal a day in a safe and effective manner requires careful planning and preparation. It’s crucial to create meal plans and pay attention to staying hydrated.
What is the OMAD Diet?
Well, think back to those days when you ended up having just one meal unintentionally. Maybe it was a busy workday filled with back-to-back meetings, surviving on cups of coffee until dinner. Or a day spent running errands and taking care of the family, grabbing breakfast but not finding time for anything else until collapsing on the couch in the evening. And hey, we’ve all had those lazy days when we slept in, had an early lunch, and then retreated back to bed to enjoy some Netflix and a nap until the next morning. (Honestly, that last one sounds pretty amazing, right?)
Now, the OMAD diet takes that concept of unintentionally eating one meal and turns it into a deliberate and mindful approach.
So, what exactly is OMAD and what does the OMAD diet entail?
We’ll dive into the details of what your one meal might consist of later on, but the basic schedule of the OMAD diet revolves around eating one meal (or one meal with some light snacks) within a one to two-hour timeframe, and fasting for the rest of the day. This means you’ll be fasting for about 22 to 23 hours and getting all your necessary nutrients through wholesome, minimally processed foods like whole grains, fruits, vegetables, lean protein, and healthy fats during that one meal.
Compared to other intermittent fasting plans, the one-meal-a-day diet has stricter fasting requirements. For example, other plans like intermittent fasting 16/8 or the Warrior Diet have longer eating windows and shorter fasting periods. Similarly, the 5:2 diet, alternate-day fasting, and eat-stop-eat intermittent fasting plans involve strict fasting on certain days while eating normally on others.
What does the research tell us about the OMAD diet?
While there is ample evidence linking intermittent fasting, including time-restricted eating, to weight loss, reduced body fat, lower blood pressure, decreased inflammation, and improved metabolic health, there is limited specific research on the effects of an OMAD diet and whether its potential benefits are short-term or long-term.
A few studies suggest that consuming one meal a day can lead to lower overall body mass and reduced fat mass. However, these studies often have small sample sizes, focus on healthy individuals, and have short durations. Furthermore, there is no evidence indicating that longer or more frequent fasting periods result in additional benefits.
In simpler terms, “more” is not necessarily “better,” so you might achieve similar results with less restriction. Life is challenging enough without making it unnecessarily tougher on yourself!
When it comes to any fasting-related eating plan, it’s crucial to remember that everyone is unique, and not everyone will experience the same benefits, if any, from intermittent fasting.
That’s why it’s important to have a clear understanding of your goals and why you’re exploring intermittent fasting in the first place. Be mindful and kind to your body throughout the process, making necessary adjustments along the way. Your body is there to support you, so it’s essential to reciprocate by providing it with what it needs to thrive.
How Does the OMAD Diet Work?
Similar to other intermittent fasting plans, the OMAD diet operates by implementing timed eating periods that help your body burn fat and boost energy levels.
Once you finish eating your meal, your body gets to work digesting the food and extracting the necessary nutrients. It enlists the help of insulin, a friendly hormone, to transport these nutrients to where they are needed. Over the following hours, your body converts the meal into various things like energy, fat, muscle, and brain power, entering a contented phase of about 8 to 12 hours after eating. After approximately 12 to 14 hours since your last meal, your body enters a fasted state where it begins using stored fat as fuel.
On a regular day, you likely don’t go more than 12 hours without eating. However, with the OMAD diet, you intentionally extend the fasting period to an impressive 23 hours before having your next meal.
While the fasting aspect of the OMAD plan may seem restrictive, here’s the good news regarding the eating window: instead of obsessing over what you eat, this eating routine focuses on when you eat. Rather than meticulously tracking macros or measuring portions, you simply need to be mindful of the clock. This structure is especially beneficial for those who dislike counting calories or have a fear of numbers, perhaps stemming from a less-than-pleasant algebra teacher back in ninth grade.
However, as exciting as it may be to enjoy whatever you want during that one-hour eating window, it’s important to carefully manage both the fasting and eating periods to ensure you’re obtaining all the necessary nutrients. This requires diligent meal planning and attention to your nutritional needs.
What should you eat on the OMAD diet plan?
While technically you can eat anything on OMAD, it’s important to focus on nutrient-dense foods like fruits and vegetables. If you’re unsure about what a one-meal-a-day plan might look like, here are some general steps to follow when meal planning within the OMAD framework.
We have provided advice on what to eat during intermittent fasting and what you can drink while fasting. In general, prioritize meals that are rich in lean protein, as protein is crucial for muscle building and maintenance. If you follow a vegan or vegetarian diet, make sure to include plant-based protein sources such as protein powders, tofu, and beans, rather than solely relying on carbohydrates.
Remember, food itself is never inherently “good” or “bad,” and you should enjoy your favorite foods without judgment or guilt. However, it is beneficial to build your meals around foods that promote health, are nutrient-dense, and minimally processed. Here are some items you can add to your shopping list:
- Lean protein sources like fish, beans, lentils, poultry, eggs, and tofu.
- Whole grains such as oats, bulgur wheat, barley, and quinoa.
- Fresh produce including fruits and vegetables.
- Dairy products like yogurt and cheese, or calcium-fortified alternatives like almond milk.
- Healthy fats found in avocados and nuts.
Additionally, staying hydrated is crucial for safe fasting. Keep zero-calorie beverages like coffee and tea on hand. While diet soda can be consumed in moderation (up to two per day), it’s recommended to limit its intake due to uncertain long-term effects. To make water more interesting, you can add mint or fresh lemon slices for a refreshing twist.
Check out our article on why you should start your day off with lemon water.
Remember, the key is to nourish your body with a variety of nutrient-rich foods while enjoying the process.
OMAD Diet and Weight Loss
There are several reasons why you might consider giving the OMAD plan a try. It could be to boost your energy levels, improve your metabolic health, or simply because you’ve had success with other time-restricted eating plans and want to explore this one. Perhaps the idea of planning multiple meals a day feels overwhelming to you.
Whatever your reasons may be, we respect your decision. However, if you’re considering OMAD for weight loss, it’s important to note that while intermittent fasting, in general, has been associated with short-term weight loss, there is limited research specifically focused on the weight loss benefits of the one meal a day approach or its long-term effects.
Moreover, intermittent fasting is not necessarily more effective than a calorie-restricted diet for weight loss. It may not lead to weight loss on its own without incorporating other lifestyle changes (although some studies suggest that fasting may have certain advantages in certain aspects of weight loss).
However, by eating only one meal a day, it is likely that you will consume fewer calories overall—primarily due to reduced volume—and this calorie deficit can potentially result in weight loss.
On the other hand, limiting your eating window to approximately one hour may increase feelings of hunger (or “hangry” grumblings) and could tempt you to overindulge or choose foods high in fat, sugar, and sodium when you finally do eat.
While there is some evidence supporting the idea that an OMAD routine may contribute to weight loss, further research is needed to fully understand its effectiveness, particularly under different conditions and durations, and how it affects individuals with different characteristics.
Ultimately, it’s essential to listen to your body, make mindful choices, and consider a holistic approach to weight loss that incorporates a balanced diet and regular physical activity.
Is it possible to exercise while following the OMAD plan?
Yes, it is generally possible to exercise while on an OMAD plan, but it requires careful management to ensure safety and optimal performance. Exerting yourself without adequate fuel in your body can be risky and may leave you feeling sluggish, overly tired, and more susceptible to food cravings.
If you intend to incorporate physical activity into your OMAD routine, it’s crucial to pay extra attention to consuming all the necessary nutrients during your one meal and maintaining proper hydration before, during, and after exercise, regardless of its intensity.
Additionally, it’s important to consider your specific goals. While engaging in physical activity during a fasted state may, in some cases, promote better metabolic flexibility and increased fat burning, it may not be suitable for endurance training or muscle building.
Above all, listen closely to your body. The idea of “no pain, no gain” is not necessarily an ideal mindset when exercising in a fasted state. Take it slowly, regularly check in with yourself, and be aware of your limitations. It’s absolutely fine if you feel the need for a snack before a leisurely walk, let alone before engaging in intense cardio workouts. Prioritize your well-being and adjust your exercise routine accordingly.
What are the health benefits and risks of the OMAD eating routine?
Understanding how the OMAD eating routine will specifically impact your body can be challenging since everyone’s health is unique. Factors such as age, lifestyle, health conditions, and physical activity levels vary from person to person. As a result, the benefits of intermittent fasting observed in studies may not necessarily apply to everyone.
Moreover, scientific research hasn’t extensively explored the question of whether one meal a day is healthy when compared to other forms of intermittent fasting. In short, it’s a complex matter.
However, the good news is that we’ve gathered scientific information on how intermittent fasting may influence your health and well-being. While these findings cannot guarantee the exact outcomes for your body or predict your individual response to the OMAD approach, they can provide you with insights into what you might expect.
Health benefits
Weight loss and improved body composition
The OMAD diet’s calorie restriction nature can lead to weight loss by creating a calorie deficit. By condensing all your daily calories into one meal, you naturally limit your calorie intake and promote fat burning. This can result in weight loss and improved body composition, including reductions in body fat and waist circumference.
Reduced inflammation
Chronic inflammation is associated with various health conditions, including heart disease, diabetes, and certain cancers. Studies suggest that intermittent fasting patterns, like the OMAD diet, can help reduce inflammation markers in the body. By giving the digestive system a break and allowing the body to focus on cellular repair, the OMAD diet may have anti-inflammatory effects.
Mental clarity and focus
Some individuals report increased mental clarity and improved cognitive function while following the OMAD diet. By avoiding frequent spikes and crashes in blood sugar levels associated with multiple meals, the body maintains more stable energy levels throughout the day. This can lead to enhanced focus, concentration, and mental alertness.
Cardiovascular health benefits
OMAD fasting may contribute to a healthier heart by lowering cholesterol levels, blood sugar levels, and insulin resistance. These factors are important in maintaining cardiovascular health and reducing the risk of heart disease and stroke.
Potential health risks
Hormonal changes
Research suggests that intermittent fasting may affect reproductive hormones differently in assigned-at-birth men and women, potentially decreasing certain hormones while not affecting others. The limited existing research fails to explore the effects of fasting on trans men and women, nonbinary individuals, and those on hormone replacement therapy.
Mood changes
While some studies indicate that intermittent fasting may reduce symptoms of anxiety and depression, others suggest it could increase negative emotions and decrease positive emotions. Initially, you may experience increased hunger, irritability, or moodiness during fasting, but these feelings typically subside after a few weeks.
Decreased concentration
The brain requires specific nutrients from food to function optimally and maintain cognitive processes. Following a fasting-based eating routine without proper meal planning may deprive the brain of essential nutrients.
Higher risk of disordered eating
Intermittent fasting can promote mindfulness and conscious eating habits, which can be beneficial for incorporating nutrient-dense foods into one’s diet. However, it may also exacerbate disordered eating tendencies or lead to an unhealthy relationship with food. It is not recommended for individuals with a history of eating disorders.
Pros and Cons of the OMAD Diet
| Pros | Cons |
|---|---|
| Doesn’t require special ingredients | Not appropriate for everyone |
| Inexpensive | Requires very careful meal planning |
| Offers an easy-to-follow structure | Difficult to manage around life |
| Can eat a very large meal | Gives less energy, so physical activity will be hard |
Is OMAD safe for everyone?
The short answer is “no.” As a highly restrictive form of intermittent fasting, OMAD isn’t suitable for everyone. Finding a food routine that works for your body and lifestyle is crucial, just like with any dietary approach. If you’re considering an OMAD plan, we strongly recommend consulting your doctor first to determine if it’s a safe and effective approach for you.
Special caution should be exercised if you are pregnant, breastfeeding, trying to conceive, have a history of disordered eating, have diabetes or other chronic medical conditions, have poor digestion or irregular digestion, are under 18 or over 65 years old, or are taking prescription medication that requires food intake. Even if you do not fall into these categories, careful and intentional planning is necessary to ensure you are obtaining adequate nutrients and not neglecting any essential dietary needs.
