The OMAD diet is a trend where a person eats only one meal per day, and this strict eating pattern has sparked both interest and concern among health experts. In this article, we examine the OMAD diet closely, including the results people report and the scientific research that reveals potential benefits and risks. We go through evidence from studies and real-world experiences to help you understand this extreme eating approach.
The OMAD diet, which stands for One Meal A Day, is a form of intermittent fasting where you fast for most of the day and consume all your daily calories within a single eating window, typically within one hour. People following the OMAD diet often drink water or zero-calorie beverages like black coffee or tea while fasting to stay hydrated and manage hunger. With this pattern, the idea is that your body will switch from receiving frequent energy to using stored fat.
Most descriptions of the OMAD diet explain it as a 23-hour fast followed by a one-hour eating period. That meal can be whatever food you choose, and proponents like the simplicity of not counting calories or managing multiple meals each day. But the simplicity of the OMAD diet also means you must be strict with your schedule, because eating outside the set time breaks the fast, and the approach changes dramatically.
Content creators and influencers have tried the OMAD diet and shared their real-world experiences. One individual documented what happened when he followed the OMAD diet for a week. He reported that sticking to one meal each day was much harder than expected, as he felt extremely hungry between workouts and social activity times. He found himself thinking about food constantly and needed caffeine to distract from hunger. Over the week, he lost weight but described the experience as very difficult and not sustainable for his lifestyle.
Reports from people trying the OMAD diet also show how social life can be affected. Eating just one meal makes joining friends at lunch or dinner times harder, and some feel isolated because they cannot participate in normal eating moments. Even if weight loss is seen in the short term, the mental and social toll can outweigh perceived benefits for many.
How the OMAD diet affects your body
When you follow the OMAD diet, your body goes through metabolic changes due to extended fasting periods. After your body uses up glucose from the meal, insulin levels drop, and your body starts burning stored fat for energy. This shift can lead to weight loss for some people as fat becomes the primary fuel source.
Scientific research on similar eating patterns shows that metabolic flexibility can improve, meaning the body becomes more efficient at switching between fuel sources like glucose and fat. One 2022 study found that eating one meal per day in the evening lowered body weight and enhanced fat oxidation during exercise without impairing physical performance.
However, this metabolic change depends on individual health and how the diet is followed. Some people may see benefits while others may struggle with negative effects on energy or mood. The OMAD diet is more extreme than typical forms of intermittent fasting and may stress the body in ways that are not fully understood.
The main reason many people try the OMAD diet is for weight loss. Because eating once a day naturally limits the number of calories most people take in, it can lead to a calorie deficit and weight reduction. Studies on fasting techniques like OMAD do suggest potential for weight loss.
Some people also report feeling more alert or focused when following the OMAD diet once they adapt to the routine. The long fasting window may reduce constant hunger pangs for a minority of people, and individuals who do not like frequent meals may enjoy the simplicity of one daily eating time.
The OMAD diet can also change eating habits by forcing people to think more about nutrition in that one meal. If the meal is nutrient-rich and balanced, you may get most of your daily requirements in a short time. Yet this is hard to do and requires careful planning.
Despite some potential benefits, major health concerns are associated with the OMAD diet. Studies show that eating only one meal per day may increase blood pressure and cholesterol levels, which are risk factors for heart disease and stroke. High blood pressure or elevated cholesterol can harm cardiovascular health over time.
There are also fears that long periods without food could spike your blood sugar after the one meal, especially if that meal is high in carbohydrates. Blood sugar spikes can be risky for people with metabolic conditions like diabetes and may stress the body’s ability to regulate glucose.
Experts also warn that the OMAD diet can cause extreme hunger, shakiness, low energy, fatigue, and difficulty concentrating. These symptoms may lead to irritability and mood swings that make daily life harder, especially for people with demanding schedules or physical jobs.
Some research suggests even more serious long-term risks. One study on time-restricted eating patterns linked very limited eating windows to a higher risk of death from cardiovascular disease compared to more balanced eating durations. While this research was not specific to OMAD, it raises caution about very tight feeding windows.
Nutrient deficiencies are another important concern. Eating just one meal can make it hard to get all the vitamins, minerals, protein, and fiber your body needs. This shortfall can lead to weakened immunity, fatigue, and long-term health issues if not carefully managed.
Healthcare professionals typically do not recommend the OMAD diet as a primary strategy for weight loss because of these potential negative effects on health. Many urge people to choose more balanced and sustainable diets that include regular meals with a variety of nutrients.
The OMAD diet may be particularly risky for people with diabetes, cardiovascular disease, or other chronic conditions. Rapid changes in blood sugar or nutrient intake can be dangerous for these groups, and long fasting periods may trigger hypoglycemia or unstable glucose levels.
Pregnant women, teenagers, older adults, and those with a history of eating disorders are also advised to avoid this type of extreme fasting. Their bodies have higher or different nutritional needs that are not well served by a single daily meal.
In addition, athletes or physically active people may find the OMAD diet limits their performance, because long fasting hours can reduce energy levels and recovery. Before trying the OMAD diet, it is important to speak with a doctor or registered dietitian.
If your goal is weight loss or better health, there are less extreme versions of intermittent fasting that may offer benefits without the same level of risk. For example, eating within an 8-hour window each day, known as time-restricted eating, allows for two or three meals and can be easier to sustain.
Other diets focus on balanced nutrition and regular meal timing without cutting out large portions of the day. These may support health and weight goals while reducing stress on your body and mind. A healthcare provider can help tailor a plan to your specific needs.
The OMAD diet has both positive and negative sides. Some people do lose weight and enjoy its simplified structure. Others find it too difficult, experience low energy, or face health setbacks. Scientific evidence on the OMAD diet is still limited and mixed, meaning researchers do not yet know the full long-term effects on health.
Before deciding to try the OMAD diet, consider your personal health, lifestyle, and goals. Discussing your plan with a healthcare professional ensures you understand potential risks and how to avoid them. For many people, balanced eating with regular meals and nutrient-rich food may be a safer and more sustainable path to wellbeing.
