Eating One Meal a Day (OMAD): Is It a Safe Weight-Loss Strategy?

The concept is OMAD: one meal a day. 

For those who are looking to lose weight and eat balanced meals, one of the first problems you run into is time. Time for sitting down, time for meal prep, time for shopping for fresh ingredients from every section of the food pyramid. It’s enough to make you wish you lived in a sci-fi world where meals were synthesized instantly, or at least you could get all the nutrients you need from one toothpaste tube full of astronaut food goo. 

What if you could concentrate all the food you need into one meal a day? Would that help you lose weight without having to think about it constantly, and more importantly, would it be safe? The OMAD diet is a real eating strategy that people are trying, and this article has the details and the answers you’re looking for.

What Is the OMAD Diet?

The one-meal-a-day diet is a form of intermittent fasting in which you restrict your eating windows of time and the amount of meals you eat. Some diets incorporate alternate-day fasting or morning fasting (such as the keto diet, high in healthy fats), and some people treat the OMAD concept as more of a daily caloric restriction. The bottom line is that to lose weight you either need to consume fewer calories than you burn, or burn more calories than you consume, and limiting your calorie intake to only what is needed each day will ultimately lead to weight loss.

OMAD is a process of retraining your body to target your fat stores for energy instead of relying on a constant intake of quick energy (like the sugars from carbohydrates). Whether or not the OMAD diet is the best diet for you depends on your personal relationship to food, your daily schedule, and whether or not you have the right tools for starting such a dramatically new way of eating like one-meal-a-day intermittent fasting.

How Does the OMAD Diet Work?

Most people starting the OMAD diet will choose dinner as their one meal a day, which means fasting between waking and that one large meal that contains all the calories of the day in healthy ratios of protein, carbs, and fats. 

Those who need more energy to function throughout the day (can’t work on an empty stomach, or chase after kids, or drive around completing the day’s chores) can either portion a certain amount of their daily calories to a midday snack or two (fruit, cheese, a hard-boiled egg, etc.), or can use certain tips and tricks well-known to those keeping a ketogenic diet. For instance, a one-meal-a-day keto hack might be starting the day with keto coffee and MCT oil to give your body digestible, fat-burning energy so you don’t feel like you’re running on fumes. No-calorie drinks like water, tea, and black coffee are also allowed during windows of fasting.

The OMAD diet is less about counting calories and more about getting the right macronutrients in your one-hour window of meal time. You want to create a calorie deficit each day but you don’t want to starve yourself. The goal instead is to retrain your metabolic rate to access body fat for energy. 

Seek medical advice if you’re not sure if this diet is right for your body’s needs, but if you can safely get into the swing of an OMAD diet, there are many fasting benefits you can gain.

The Benefits of One-Meal-a-Day Dieting

There are a few studies that suggest specific benefits from fasting diets. They include:

• A 2011 study that found that restricting one’s daily calories by 20-25% is associated with more stable blood sugar levels and improved heart health, because it decreases your glucose levels and increases insulin sensitivity.
• A study from 2017 shows that those with diabetes who practiced intermittent fasting for 6 weeks improved their body weight and fasting blood sugar levels.
• In a 2-year follow-up study completed in 2017, which compared daily caloric restriction to intermittent fasting, fasting was shown to be a beneficial strategy for those with insulin resistance or prediabetes. 
• A 2011 study demonstrated that restrictive eating helps with memory retention in older participants, along with increasing their longevity via reducing disease-causing processes.

One-meal-a-day fasting has also been said, on an anecdotal basis, to help increase daily energy, satiety, and eliminate the phenomenon known as the “midday slump,” but there is no scientific data for this claim.

OMAD Downsides and Possible Side Effects

Any form of fasting diet—be it alternate-day, intermittent, or otherwise—could come with the following downsides and symptoms.

• Shakiness
• Brain fog
• Trouble concentrating
• Fatigue
• Feelings of weakness
• Extreme hunger
• Binge eating

It is hard to retrain a lifetime of habits, and fasting isn’t right for everyone. Those with hypoglycemia or diabetes should consult with a medical professional before manipulating their diet too much, and some people might find that denying themselves food all day is too maddening to tolerate. Every one of us is built differently, and there’s no one-size-fits-all solution to effective dieting.

One 2017 study focusing on alternate-day fasting found that this form of dieting had the highest dropout rate due to these difficulties and more. Some of the side effects can range from irritability to dangerous instances of binge eating, which could develop into an eating disorder. 

If the OMAD diet works for you, embrace it, but if it doesn’t, there are other diets like Paleo, Atkins, and keto that might be a much better match for your needs. Stay calm and shop around!

Other Healthy Weight-Loss Strategies

Even if a one-meal-a-day diet works for you right now, it might not be sustainable forever, and there’s no need to force it if you’re just not feeling it anymore. Keeping to an unyielding diet that no longer benefits you could cause more harm than good, including severe calorie restriction, metabolic disruption, and the development of eating disorders. In your efforts to lose weight healthily, just keep these simple, time-tested tips in mind.

• Track and measure your food. One great way to understand where your calories are coming from and what a correct portion size actually looks like is to count calories for a month or so and weigh your food using a kitchen counter scale. This will go a long way in educating you about what foods are worth your time and calorie allotment. 
• Start an exercise routine. You don’t even have to join a gym for this. Taking up a habit of daily walks or at-home exercises that use your own body weight to build strength will increase the number of calories you burn and help you lose weight and feel great.
• Join a support group. Whether for dieting, fitness, or weight-loss goals, having accountability buddies and a like-minded support group can make the difference in sticking with your new healthy habits.

One Meal a Day for Weight Loss

Check with your doctor before you try a fasting diet, and always be sure to listen to your body when it comes to changes in fitness routines or in food choices. Remember that trying something that doesn’t work out is not failing, it’s experimenting, and with enough experimenting under your belt, you’ll be able to refine the foods and timing that work for your life, your weight-loss goals, and your overall well-being.