One Meal A Day: Benefits & Risks

by Marixie Ann Obsioma, MT, undergrad MD on April 6, 2022
Last updated on May 4, 2022

Many people swear by eating only one meal each day to lose weight and enhance their overall health. The one-meal-per-day (OMAD) diet is also known as the one-meal-per-day diet.

One Meal A Day: Benefits & Risks

Although the meal’s quantity and timing may vary depending on personal preference, people on the OMAD diet typically limit their calorie intake to a single meal or a brief period.

Fasting – reducing calorie intake for a specific period — and calorie restriction, in general, are the primary health benefits of OMAD.

How does it work?

Intermittent fasting can take numerous forms, and OMAD can be done in various ways.

Two examples are having only one meal and fasting for the rest of the day or having one dinner and consuming minimal food during fasting intervals.

This diet causes a calorie deficit, which can help you lose weight.

Fasting can lower heart disease risk factors, lower blood sugar, and reduce inflammation, among other health benefits.

However, compared to other intermittent fasting approaches, such as the 16/8 method, which incorporates 8-hour eating windows and 16-hour fasting windows, eating only one meal each day is one of the most extreme.

Several popular diets recommend only eating one meal every day. The Warrior Diet, for example, requires a person to consume only one meal each day, cycling between extended periods of fasting and brief intervals of calorie ingestion.

Most people who follow the OMAD diet only eat dinner, while others only eat breakfast or lunch. In addition to the one meal, some versions of this eating pattern allow for a snack or two.

Some OMAD followers, on the other hand, don’t eat anything with calories during their fasting window and only eat calories during their designated meal, which lasts about one hour.

Loss of weight

You must establish an energy deficit to lose weight.

This can be accomplished by either boosting your calorie burn or decreasing your calorie intake. Regardless of how it is achieved, calorie restriction will result in fat reduction.

People who follow the OMAD approach are more likely to lose weight because they consume fewer calories than in a conventional eating pattern.

For example, in research on healthy adults, reducing calorie intake to 4 hours in the evening resulted in considerably more body fat loss than eating three different meals during the day.

Intermittent fasting significantly extended fasting periods such as OMAD have also been demonstrated to help people lose weight in studies.

However, it did not appear to be any more effective than typical calorie restriction approaches, such as limiting calories at each meal.

Research of 50,660 persons found that those who ate 1 or 2 meals per day had a lower body mass index (BMI) year after year than those who consumed three meals per day.

In comparison to shorter fasting periods, an overnight fast of 18 or more hours was related to lower body weight, according to the study.

However, these weight-loss benefits are associated with intermittent fasting in general, not only the OMAD.

Additionally, extreme fasting methods like OMAD may have adverse effects that people should be aware of, such as increased hunger and significant metabolic alterations.


Fasting has been related to some other health benefits and weight loss. Fasting, for example, may help lower blood sugar levels and some heart disease risk factors, such as LDL “bad” cholesterol.

Fasting has also been linked to lower inflammatory indicators, including C-reactive protein.

Fasting may also have specific advantages for the nervous system’s health. According to animal studies, it may halt neurodegeneration and improve longevity.

However, while these potential benefits are exciting, it’s crucial to remember that they are generally linked to fasting, not OMAD.

Several studies suggest that the OMAD diet is worse for your health than other, less rigorous fasting approaches.


Although fasting and calorie restriction have been linked to a range of health benefits, some evidence suggests that restricting too much — which might involve only eating one meal per day — may do more harm than good.

Compared to regular eating patterns or less extreme fasting regimens, this severe restriction may result in higher total and LDL “bad” cholesterol and blood pressure levels.

In comparison to having three meals per day, other studies have found that eating one meal per day may increase fasting blood sugar levels, delay the body’s reaction to insulin, and increase the appetite-stimulating hormone ghrelin.

This can result in severe hunger.

Furthermore, limiting calories to one meal per day may raise the risk of hypoglycemia, or low blood sugar, particularly in people with type 2 diabetes.

In addition to these risks, eating only one meal per day might cause symptoms such as:

  • Nausea
  • Dizziness
  • Irritability
  • Low energy
  • Constipation

Many people, including pregnant or breastfeeding, infants and teenagers, elderly adults, and persons with eating problems, should avoid the OMAD diet.

Limiting one meal a day can lead to disordered eating, hurt a person’s social life, and be extremely difficult to stick to for most people.

Furthermore, getting adequate nutrients in one meal can be difficult. This can lead to nutrient shortages, severely impacting your health and putting you in danger.

Finally, some people who follow the OMAD diet binge on highly processed, calorie-dense items such as fast food, pizza, doughnuts, and ice cream during their one meal.

While one can incorporate these meals into a healthy lifestyle, eating only foods high in added sugar and other unhealthy nutrients will negatively impact your health.

Although there are benefits related to fasting and calorie restriction, research has shown that consuming 2 or 3 meals per day is likely a better option for overall health than eating one meal a day.

Foods to consume and stay away from

Whatever dietary plan you follow, whole, nutrient-dense foods should make up most of your diet.

Although most health professionals do not recommend eating only one meal each day, if you do choose this eating pattern, it’s critical to eat a variety of nutritious meals, such as:

  • Fruits, such as berries, citrus fruits, and bananas
  • Vegetables, such as kale, broccoli, cauliflower, asparagus, and peppers
  • Starchy vegetables and grains, such as sweet potatoes, butternut squash, oats, quinoa, and barley
  • Healthful fats, such as avocados, olive oil, and unsweetened coconut
  • Legumes, such as peas, chickpeas, lentils, and black beans
  • Seeds, nuts, and nut kinds of butter, such as cashews, macadamia nuts, almonds, and pumpkin seeds
  • Dairy and plant-based alternative products, unsweetened yogurt, coconut milk, and cashew milk
  • Protein sources, such as chicken, fish, tofu, and eggs

Limit foods that have been heavily processed, such as:

  • Fast food
  • Sugary baked goods
  • White bread
  • Sugary cereals
  • Soda
  • Chips

These meals are low in nutritional content, and consuming them frequently can lead to weight gain and an increased risk of disease.

The OMAD diet requires people to eat as little as possible during fasting times.

This indicates a total calorie restriction on the OMAD diet. During fasting periods, you can still drink water and other non-calorie beverages.

Others prefer low-calorie, high-protein snacks throughout the day, such as:

  • Whites of eggs
  • Chicken
  • Tuna

Again, most healthcare specialists advise against having only one meal each day because it might harm one’s general health.

If you’re thinking about trying this dietary pattern, seek guidance from a reputable healthcare expert first.

Menu Sample

Unless carefully planned, eating one meal a day is unlikely to provide your body with the calories and nutrients required to survive. Choosing to eat over a more extended period may assist you in increasing your nutrient intake.

If you decide to attempt eating one meal a day, don’t make it a habit to do it seven days a week.

Most people do the OMAD diet for a few days a week, alternating it with a regular diet or a less rigorous intermittent fasting strategy like the 16/8 method.

If you only eat one meal a day, make it as nutrient-dense as possible. These meals should include at least 1,200 calories, which might be challenging for some people to consume in a single sitting.

If you find it challenging to consume enough calories in one sitting, consider extending your eating window by an hour or two and splitting your meal into two smaller portions. This will allow you to consume adequate nutrients and calories without being excessively satiated.

Here are some examples of nutritionally full meals that will likely exceed 1,200 calories if portion sizes are large enough:

  • Baked chicken with butter-topped mashed sweet potatoes and olive oil-roasted broccoli, followed by full-fat Greek yogurt with berries, nuts, seeds, and honey.
  • Fruit served with nut butter, hemp seeds, and coconut flakes, followed by grilled salmon topped with guacamole, brown rice, black bean salad, and roasted plantains.
  • Egg omelet with goat cheese, avocado, coconut oil-grilled vegetables, crispy baked potato wedges, and dark chocolate-dipped fruit with whipped cream aside.

As you can see, each meal should include foods from all food categories.

  • Carbohydrates
  • Fats
  • Proteins

A general rule of thumb is to consume 1,200 calories each day. To maintain their weight, most individuals require far more.

Due to the number of calories that must fit into a single meal, eating is significantly more challenging for individuals following specific dietary patterns, such as vegan or low-fat diets.

Overall, no matter your health goal, trying to jam all of your calorie demands into one meal is not required. This eating pattern is also unsustainable and impractical for the majority of people.

Why Isn’t It a Good Idea to Starve Yourself to Lose Weight?

You’ve probably heard “calories in versus calories out” as the only way to lose weight if you listen to the many fitness gurus online.

While the adage has some truth, it falls short of adequately explaining the healthiest and most successful methods for achieving long-term weight loss.

As a result, many people have turned to calorie deprivation, which can be highly damaging to one’s health.

In this article, you’ll learn why starvation isn’t a healthy weight-loss strategy and how to replace it with better options.

What’s the Difference Between Intermittent Fasting and Starvation?

If you’re unfamiliar with the concept, you can mistake intermittent fasting for starvation. Intermittent fasting, when done correctly, can be a beneficial and long-term habit.

Intermittent fasting is a type of eating that alternates between times of “eating” and “fasting.” The most common form, for example, is 16:8, which includes an 8-hour eating window and 16 hours of fasting.

While intermittent fasting can aid weight loss, the idea is not to restrict calories excessively. Instead, you simply eat your average daily calories or a minor calorie deficit over a shorter period each day.

On the other hand, starving is commonly characterized as going without food for an extended time or eating much less than your body’s daily calorie demands. This results in a significant calorie deficit in your body, which will lead to unsustainable weight reduction.

Dietitians define a deficient calorie diet as ingesting 450–800 calories per day or less, which isn’t healthful or sustainable in the long run. As a result, depriving your body of calories may result in various health problems and is not recommended.

Intermittent fasting is described as eating food for a set amount of time, whereas starving is not eating at all or eating very few calories for a lengthy time.

What Happens to Your Body If You Become Hungry?

To lose weight, your body must be in a calorie deficit, burning more calories through exercise while eating fewer calories. On the other hand, a higher calorie deficit does not always imply that you will lose weight and keep it off.

Though you may lose a large amount of weight at first, you may find it challenging to maintain this weight loss in the long run.

Even worse, if you starve yourself, your body’s survival mechanisms may adapt to extreme calorie shortages. In the first place, this may obstruct your targeted weight loss plan.

The rate of your metabolism slows.

Under long-term calorie restriction, your body begins to use fat stores as a significant energy source and muscle and skeletal tissue as secondary energy sources.

Adaptive thermogenesis reduces your resting metabolic rate (RMR) over time as a result of calorie restriction (metabolic adaptation). In order to conserve as much energy as possible, your body becomes less effective at burning calories.

This was demonstrated in a groundbreaking study involving 14 contestants from “The Biggest Loser.” Participants lost an average of 129 pounds (58.3 kg) throughout the 30-week show, and their RMR reduced from 2,607 to 1,996 calories per day.

Despite regaining 90 pounds (41 kg), their average RMR (1,903 calories per day) remained depressed.

These findings indicate that they would have to consume fewer calories and expend more calories to maintain weight, making weight loss more difficult.

However, new research suggests that metabolic adaptability fades once you’re no longer in a calorie deficit. Most weight regain is assumed to be related to excessive calorie consumption, which could be owing to increased hunger and a feeling of “liberation” from calorie restriction.

Furthermore, a decreased metabolic rate may cause you to become fatigued more quickly. This is a defensive technique your body uses to keep you from using too much energy. To encourage you to eat, your body stimulates the release of hunger hormones.

Your body will strive hard to avoid further weight loss by decreasing your metabolism, especially if you’ve been fasting for a long time.

Your body is less efficient.

Your body may begin to prioritize critical biological activities like breathing and heart rate while slowing down nonessential bodily processes like:

  • Hair and nail growth. Your hair and nails may become brittle.
  • Immunity. Your immune system may have a more complicated time-fighting infection and illness.
  • Digestion and hunger regulation. You may experience irregular or intensified hunger, recurring bloating, or stomach discomfort.
  • Reproductive health. Your menstrual cycle may change or stop.
  • Skin health. You may experience improper or delayed wound healing or premature aging.
  • Bone health. Your bones may become weakened.

Hunger causes your body to enter an unhealthy state that it badly wants to escape. Though you may initially lose weight, your body requires enough calories to function correctly and work hard to promptly restore your weight and health.

It could be harmful to your mental health.

Starvation and other harmful dieting patterns can hurt one’s mental health.

Starvation dieting can lead to disordered eating behaviors such as food restriction, dread of food choices, a negative relationship with food, excessive exercising, and a fixation with body weight and size.

In difficult situations, prolonged fasting can lead to an eating disorder like anorexia nervosa, bulimia nervosa, or binge eating disorder.

It’s critical to speak with a healthcare practitioner if you think you’re developing an eating disorder or disordered eating patterns. They can recommend you to a specialist. You can also get help through the National Eating Disorders Association Helpline.

It is not healthy or sustainable to deprive your body of calories. It may slow down your metabolism, make your body less efficient, and lead to disordered eating habits over time.

Tips for A Healthy Weight Loss

Rather than jeopardizing your health for weight loss, you should focus on developing good, long-term behaviors.

Here are some science-backed techniques to help you lose weight and keep it off:

  • Aim for a slight calorie deficit. Most research suggests a 10–20% deficit is sustainable and manageable. For example, if your maintenance calories are 2,500 calories per day, aim for a deficit of 250–500 calories per day through a healthy diet and exercise.
  • Increase physical activity. Aim for strength training and cardiorespiratory exercise (running, walking, etc.) for at least 200 minutes per week, or about 30 minutes each day.
  • Add strength training to your routine. Strength training helps preserve and build muscle tissue during weight loss. Building more muscle mass can increase your metabolism.
  • Limit processed foods. Try to make most of your meals from whole, minimally processed foods, usually lower in calories and higher in protein, fiber, and healthy fats to promote fullness.
  • Eat more protein. A high protein diet can help preserve muscle tissue during a calorie deficit.
  • Drink mostly water. Limit sugary beverages, energy drinks, and specialty drinks, which tend to be high in sugar and calories. Instead, opt for water, flavored water, coffee, and tea most often.
  • Go slow. Most research shows that a sustainable and healthy rate of weight loss is around 1–2 pounds (0.45–0.9 kg) per week. Therefore, slowly add new healthy habits to help you stick to your weight loss goals.

The best diets are those that are inexpensive, fun, and long-lasting. Keep in mind that not all weight loss is beneficial. Concentrate on adopting healthy lifestyle habits that help you feel energized and enjoyable.

It’s not healthy or sustainable to starve oneself for weight loss. A healthy, long-term weight loss goal is to lose 1–2 pounds (0.45–0.9 kg) per week by consistently eating a well-balanced diet to achieve a slight calorie deficit.

The bottom line

It’s not healthy or sustainable to starve oneself for weight loss.

While it may be tempting to go without eating, your body will suffer. Your body’s metabolism may slow down, your body may not work correctly, and your mental health may suffer from prolonged famine. Though you may lose weight, you will almost certainly gain it back.

Work with a health expert if you’re having trouble establishing good eating habits or if you’re noticing any worrying eating behaviors.


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