Is Eating One Meal a Day a Safe and Effective Way to Lose Weight?

Consuming a single meal each day is a form of intermittent fasting that confines caloric intake to a limited time frame. This approach can promote weight loss and may offer other health advantages.

Many people adopt eating just one meal daily to shed pounds and enhance general well-being. This eating pattern is commonly called OMAD (one meal a day).

While the composition and timing of that meal differ by individual choice, OMAD followers usually limit their daily calories to a single sitting or a brief eating window.

The possible health advantages of OMAD stem mainly from the fasting element — limiting calories during specified hours — and overall calorie reduction.

How it works

Intermittent fasting comes in many forms, and OMAD can be implemented in several ways.

Some people eat one full meal and fast the rest of the day, while others have one main meal and allow minimal eating during fasting intervals.

This strategy typically produces a calorie shortfall, which can result in weight loss.

Other fasting-related health improvements may include lowering risk markers for heart disease, reducing blood glucose, and decreasing inflammation.

Compared with less restrictive schedules like the 16/8 method — which involves an 8-hour eating period and 16-hour fast — eating only one meal daily is among the most rigorous intermittent fasting approaches.

Certain popular plans advocate eating one meal a day. For instance, the Warrior Diet has people alternate extended fasting with a brief period of eating a single daily meal.

Many OMAD adherents prefer dinner as their sole meal, though some choose breakfast or lunch. Some versions permit one or two small snacks in addition to the main meal.

Yet, some people practicing OMAD avoid all calorie-containing foods during the fasting span and only consume energy during their selected meal, typically lasting about an hour.

Weight loss

Weight loss requires creating an energy deficit.

You can do that by burning more calories or cutting the calories you consume. Any form of calorie restriction will result in loss of body fat.

Individuals practicing OMAD often lose weight because their total daily calorie intake is lower than it would be with a conventional eating pattern.

For example, research in healthy adults with lean body types found that limiting calories to a 2-hour evening window (5 p.m. to 7 p.m.) produced significantly greater reductions in body fat and total body weight than consuming three meals across the day.

Other studies indicate that intermittent fasting, including extended fasting periods like OMAD, generally leads to weight loss.

However, intermittent fasting does not appear to be substantially superior to classic calorie-reduction strategies, such as cutting calories across multiple meals.

One large study collecting dietary data from 50,660 adult Seventh-day Adventist Church members aged 30 and older in the U.S. and Canada observed that those eating 1 or 2 meals daily experienced greater annual decreases in body mass index (BMI) than those eating 3 meals per day.

The same research noted that overnight fasts of 18 hours or more correlated with lower body weight compared with shorter fasting periods.

These weight loss outcomes relate to intermittent fasting generally, not OMAD alone.

Moreover, extreme fasting approaches like OMAD can cause reductions in lean body mass.

This pattern may not be optimal for preserving or building muscle. Losing lean mass is linked to higher risk of metabolic conditions such as type 2 diabetes, cardiovascular disease, and dyslipidemia.

Benefits

Beyond weight loss, research has connected fasting with other health positives. For instance, fasting may lower blood glucose and some heart disease risk factors like LDL (“bad”) cholesterol.

Fasting has also been associated with reductions in inflammatory markers, including C-reactive protein.

Additionally, fasting might offer benefits for nervous system health — potentially slowing neurodegeneration and promoting longevity.

However, these promising effects are linked to fasting overall, rather than OMAD specifically.

In fact, some evidence shows OMAD may have more negative health effects than less severe fasting schedules.

Downsides

Although fasting and calorie restriction have been tied to various health benefits, too much restriction — such as eating just one meal daily — might be harmful.

Some studies suggest this extreme limitation could raise total and LDL cholesterol and increase blood pressure compared with regular eating patterns or milder fasting methods.

Research involving middle-aged, moderately weighted men and women who ate at scheduled times without caloric restriction suggests that eating one meal a day may elevate fasting glucose, delay insulin response, and increase ghrelin (the hunger hormone) relative to eating three meals daily.

This approach can provoke intense hunger.

Furthermore, limiting calories to a single meal may heighten the risk of hypoglycemia (low blood sugar), particularly in people with type 2 diabetes.

Besides these possible harms, OMAD can produce symptoms such as:

• nausea
• dizziness
• irritability
• low energy
• constipation

OMAD is not suitable for many populations, including pregnant or breastfeeding people, children and adolescents, older adults, and individuals with eating disorders.

Also, some who follow OMAD may overindulge in ultra-processed, calorie-dense foods like fast food, pizza, doughnuts, and ice cream during their single meal.

While these items can occasionally fit into a balanced diet, consistently eating foods high in added sugars and low in nutrients will harm long-term health.

Overall, although fasting and calorie reduction have benefits, evidence suggests consuming two or three meals daily is likely better for overall health than restricting to one meal a day.

One study even linked eating a single meal daily with higher risk of all-cause mortality and death from cardiovascular disease.

Foods to eat and avoid

Regardless of your diet, most of your intake should come from whole, nutrient-rich foods.

Although many health experts would not advocate eating only once per day, if you opt for OMAD it’s crucial to include a variety of nutritious choices such as:

• fruits, like berries, citrus, and bananas
• vegetables, including kale, broccoli, cauliflower, asparagus, and peppers
• starchy vegetables and whole grains, such as sweet potatoes, butternut squash, oats, quinoa, and barley
• healthy fats, like avocado, olive oil, and unsweetened coconut
• legumes, such as peas, chickpeas, lentils, and black beans
• seeds, nuts, and nut butters, for example cashews, macadamias, almonds, and pumpkin seeds
• dairy and plant-based alternatives, such as unsweetened yogurt, coconut milk, and cashew milk
• protein sources, like chicken, fish, tofu, and eggs

Limit highly processed items such as:

• fast food
• sweet baked goods
• white bread
• sugary cereals
• soda
• chips

These foods provide minimal nutrition, and frequent consumption can contribute to weight gain and higher disease risk.

During fasting windows, OMAD typically requires minimal calorie intake.

Under strict OMAD rules, this means no caloric intake during fasting. Noncaloric drinks like water, black coffee, and unsweetened tea are allowed.

Some people opt to eat low-calorie, high-protein snacks during the day, such as:

• egg whites
• chicken
• tuna

Again, most clinicians do not recommend eating one meal a day because it can seriously impair overall health.

If you’re thinking about trying OMAD, talk with a qualified healthcare provider before beginning.

Sample menu

It’s difficult to meet your calorie and nutrient needs with one meal unless that meal is planned carefully. Extending the eating window can help increase nutrient intake.

If you attempt OMAD, it’s generally not advisable to do it every day; discuss your plan with a healthcare professional.

Many people practice OMAD intermittently — a few days per week — alternating it with regular eating or less restrictive intermittent fasting like 16/8.

Try to make that single meal nutrient-rich. Meals should aim to provide at least 1,200 calories, which can be hard to consume in one sitting for some individuals.

If you struggle to eat enough in one meal, lengthen the eating window slightly and split the meal into two smaller portions. This helps you reach calorie and nutrient goals without becoming overly stuffed.

Examples of nutrient-dense single meals that can exceed 1,200 calories if portions are generous include:

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

Each meal should cover all macronutrient groups and include:

• carbohydrates
• fats
• proteins

Daily intake of 1,200 calories is a rough minimum; most adults require considerably more to maintain weight.

Note that this style of eating is particularly challenging for those on restricted diets (for example, vegan or low-fat plans) because fitting enough calories into a single meal can be hard.

Overall, concentrating all caloric needs into one meal is unnecessary for most goals and is often impractical and unsustainable.

Frequently asked questions

Is it healthy to eat one meal a day?

While OMAD can be a method for weight loss, it’s generally not recommended for overall health.

Restricting intake to one meal can foster disordered eating behaviors, disrupt social eating, and be very difficult to adhere to long-term.

Additionally, getting adequate nutrients in a single meal is challenging and may cause deficiencies with serious health consequences.

Why am I not losing weight if I only eat once a day?

If you eat only one meal daily, you might overconsume during that meal if you don’t monitor portions.

Your one meal must be well-balanced. Heightened hunger can increase the temptation to binge on processed, high-carb foods, raising total calories, particularly if physical activity is low.

What is the 23-hour fast every day?

This variation of OMAD confines eating to a single hour each day, with fasting for the other 23 hours.

Bottom line

Although extended fasting can deliver certain health benefits, similar outcomes can often be achieved through more sustainable strategies.

Alternatives include 16/8 intermittent fasting or simply following a nutritious, reduced-calorie eating plan if you need to lose weight.

Most healthcare professionals advise against OMAD because of its extreme nature.

People can support better overall health through methods that are more sustainable and less restrictive.