Is Eating One Meal a Day Safe? (2024)

The “One Meal a Day” diet, or OMAD diet, claims to help you lose weight by forcing your body to burn fat. It’s a type of intermittent fasting, which alternates between periods throughout the day in which you can eat anything and periods in which you don’t eat at all.

OMAD is particularly strict because you don’t eat for 23 hours, then consume all of your calories in a single meal.

How It Works

Like other kinds of intermittent fasting, eating one meal a day is a way of manipulating how your body finds and uses fuel. When you eat in a more traditional pattern, your energy comes from the food that you eat.

When you take in carbohydrates, your body breaks them down into sugars. If you have more sugar in your blood than you need, a chemical called insulin will carry the extra into your fat cells.

When you don’t eat for extended periods of time, your body produces less insulin. Your cells still need energy for fuel, so your fat cells release energy to compensate. For this to happen, however, you have to avoid eating for long enough that your insulin levels drop.

The Pros

Research on intermittent fasting is promising. The OMAD diet isn’t a magic bullet, but it may help some people to achieve their weight loss goals.

It may help you to burn fat. Study participants who tried eating one meal a day ended up with less total body fat. This particular group of people didn’t experience significant weight loss.

That said, intermittent fasting in general has proven to be an effective weight-loss method. The typical weight loss is 7 to 11 pounds over 10 weeks.

It can improve your metabolism. In adult men with prediabetes and obesity, a 6-hour period of eating followed by 18 hours of fasting improved their blood sugar levels.

It's worth noting that these men followed a more general time-restricted eating plan, and not a strict OMAD diet. More research would be necessary to know whether eating one meal a day has the same effect.

You could feel more alert. When you fast during daylight hours, your body releases more of a chemical called orexin-A, which makes you feel more alert. This also isn’t specific to OMAD, and it wouldn’t apply if you ate your single meal in the morning.

Eating in the morning and fasting overnight can help you lose weight. The OMAD diet doesn’t tell you which meal to eat. That said, people who fast overnight and eat a larger meal in the morning tend to lose more weight than people who eat more at dinnertime.

The Cons

This diet is strict, and there’s no conclusive evidence that eating one meal a day works for weight control. Whether it’s worth the discomfort depends on your tolerance and body chemistry.

It can be difficult to sustain. Intermittent fasting regimens like OMAD have a dropout rate of up to 65%. It’s no easier to follow than other calorie restriction plans.

It may make you hungrier. When you eat one meal a day rather than three, your body produces more of a hormone called ghrelin, which makes you feel hungry.

It’s no more effective than calorie reduction. Even if the OMAD diet makes you feel hungrier, it’s unlikely to lead to more weight loss than if you simply reduced the number of calories you took in during the day.

Safety Concerns

For most people, there are no serious dangers involved in eating one meal a day, other than the discomforts of feeling hungry. That said, there are some risks for people with cardiovascular disease or diabetes.

Eating one meal a day can increase your blood pressure and cholesterol. This occurred in a group of healthy adults who switched to one meal a day to participate in a study. If you already have concerns in either area, eating just once a day might not be safe.

Eating one meal late can cause your blood sugar to spike. Some OMAD studies have asked people to eat their single meal between 4 p.m. and 8 p.m. These participants had morning blood sugar levels that were higher than normal, and their bodies were less able to deal with this extra sugar.

Fasting can cause blood sugar crashes. Fasting of any type increases the risk of extremely low blood sugar, also known as hypoglycemia, in people who have Type 2 diabetes.

The safety and effectiveness of any weight-loss plan are unique to each person. It’s best to speak with a doctor one-on-one if you have questions or concerns about trying the "One Meal a Day" diet plan.

Is Eating One Meal a Day Safe? (2024)


Is Eating One Meal a Day Safe? ›

For most people, there are no serious dangers involved in eating one meal a day, other than the discomforts of feeling hungry. That said, there are some risks for people with cardiovascular disease or diabetes. Eating one meal a day can increase your blood pressure and cholesterol.

Is it safe to eat one meal a day? ›

Eating one meal a day may be a popular way to lose weight, but it's likely not a good idea for overall health. Although fasting in general — including prolonged fasting — may benefit health in a number of ways, people can reach the same health benefits using much more sustainable methods.

Is eating one meal a day hood? ›

In short, it's not recommended. The one meal a day or OMAD diet is an extreme type of intermittent fasting (IF). It's not practical for most people as it's difficult to eat enough calories and get enough nutrients in one sitting.

What is one meal you can eat everyday? ›

OMAD is a type of intermittent fasting diet in which all the calories your body requires per day are consumed in a single meal or within a 1 to 2-hour window. You're expected to fast for the remaining hours of the day until the next meal. For OMAD to work well, eating at the same time of the day is recommended.

Is it bad to eat one unhealthy meal a day? ›

It's normal and acceptable to enjoy an indulgent meal from time to time, just don't make it a regular occurrence. Don't think of a bad meal as cheating, but rather as a “conscious indulgence.” As long as you follow a healthy diet 90 percent of the time, you can have a “conscious indulgence” two to three times a week.

What happens if you don't eat for a day but drink water? ›

If you're fasting and only drinking water, you may chalk symptoms like headaches, nausea, weakness, and fatigue up to your hunger, but it could actually be a life-threatening problem if left untreated, he says.

How much weight will I lose if I eat one meal a day for 2 weeks? ›

How Much Weight Will I Lose If I Eat One Meal a Day? You may lose anywhere between 0.5-2 pounds per week if you consistently consume fewer calories than your body burns. This estimate is based on a daily calorie deficit of 500-1000 calories, which is considered a safe and sustainable rate of weight loss.

Which celebrities eat one meal a day? ›

Fans of Omad include Bruce Springsteen and Coldplay frontman Chris Martin. Many proponents of Omad claim it helps them better manage their weight and keep fit.

How many times a day should you eat to stay healthy? ›

However, a new school of thought has emerged that recommends eating larger, less frequent meals. So how often should you be eating? The Theory: Nutrition experts tend to recommend eating 3 balanced meals (350 to 600 calories each) and 1 to 3 snacks per day (between 150 and 200 calories each).

How to lose 10 pounds in a week? ›

To lose 10 pounds in one week, you'll need to burn between 3,500 and 5,000 calories more than you consume each day by restricting your diet to small portions of nutritious yet low-calorie foods, and significantly increasing your aerobic exercise with interval training, sports, and other vigorous activities.

What happens if you eat one meal a day for 30 days? ›

Safety Concerns. For most people, there are no serious dangers involved in eating one meal a day, other than the discomforts of feeling hungry. That said, there are some risks for people with cardiovascular disease or diabetes. Eating one meal a day can increase your blood pressure and cholesterol.

What is the cheapest meal you can live by? ›

Cheapest Foods to Live On:
  • Oatmeal.
  • Eggs.
  • Bread.
  • Rice.
  • Bananas.
  • Beans.
  • Apples.
  • Pasta.

What is a person who eats one meal a day? ›

The one-meal-a-day diet (OMAD) — also known as 23:1 intermittent fasting — may help people lose weight and body fat. However, eating one meal a day can lead to hunger and cravings and may not be suitable for everyone. When following this diet, a person will eat only one meal a day. This is usually dinner.

Can eating one meal a day cause problems? ›

Furthermore, restricting calories to only one meal a day may increase the risk of hypoglycemia or low blood sugar, especially in people with diabetes. In addition to these potential side effects, eating one meal a day can lead to symptoms including: nausea, dizziness, irritability, low energy, constipation.

Is it healthy to only eat 1 meal a day? ›

Not everyone is suitable for the 1 meal a day diet. Many studies have shown that eating once a day can increase blood pressure and cholesterol levels. Especially if your one-meal diet consists of only fried foods that are highly processed or contain too many simple carbs.

Can one meal raise blood pressure? ›

Eating is not usually a cause of sudden high blood pressure spikes, but for some people, it does cause a slight increase. If you're dealing with blood pressure problems and have found a connection between eating and high levels, there are some lifestyle changes you can make to help.

Is it bad to eat one meal every other day? ›

Is alternate-day fasting safe? Studies have shown that alternate-day fasting is safe for most people. It doesn't result in a greater risk for weight regain than traditional, calorie-restricted diets ( 16 ).

What happens if you don't eat for 24 hours? ›

What does a 24-hour fast do for your body? If a person fasts for 24 hours, the body runs out of its stored energy source, known as glycogen. Fat and protein are then used as an energy source. Effects on the body include weight loss, preventing certain diseases, and improving cardiovascular health.

How long is it safe to fast? ›

To keep yourself safe, especially if you are new to fasting, consider limiting your fast periods to 24 hours or fewer and keeping a snack on hand in case you start to feel faint or ill. If you do become ill or are concerned about your health, make sure you stop fasting straight away.

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