- The OMAD
diet is a form ofintermittent fasting where you eat in the same 1-hour window each day. - It's recommended you consume your one meal after your most active part of the day.
- Children, elderly, and people with
health conditions like diabetes should not try the OMAD diet.
The One Meal A Day (OMAD) diet is an extreme version of time-restricted eating, like $4. However, unlike intermittent fasting, which usually allows a four or eight-hour eating window, the OMAD diet has a one-hour eating window. So you fast for the other 23 hours of the day.
Although various forms of $4 have been shown to be an effective way to shed pounds, the OMAD diet is not recommended by nutritionists and can even be dangerous for people with certain health problems. Here's what you need to know.
What to eat on the OMAD diet
The OMAD diet does not restrict the types of food or how many calories you can eat during that one-hour eating window. However, you should aim to consume the recommended amount of calories for $4.
"Generally speaking, if only eating one time per day, one should consume the amount of calories required to meet their daily energy needs in that meal," says $4, CSSD, a registered dietitian and certified specialist in sports dietetics. "Most adults should not consume under 1,200 calories per day," she says.
It sounds obvious, but getting enough calories is extremely important as too little may $4 and break down muscle mass as the body resorts to other ways to maintain energy reserves, says Hampton.
It's important to maintain proper hydration when on the OMAD diet. The diet allows water, $4, or tea consumption throughout the day, but no other beverages, like low-calorie or $4, are allowed.
It's also recommended that you eat your meal at the same time every day to ensure a consistent 23-hour fasting period.
"It would be best to consume this meal following your most active time per day. This will help your body recover from exercise and replace nutrients that may have been lost during activity," says Hampton.
To give you some idea of what a meal on the OMAD diet might look like, here are two examples of a morning and evening meal. Please note, these are merely to illustrate what a healthy meal may look like and are not recommendations.
Morning meal:
- 680 Calories: 1 cup of oatmeal ($4) made with 1 cup 2% milk ($4) topped with 1 cup fresh, sliced strawberries ($4), ¼ cup walnuts ($4)
- 685 Calories: 3-egg omelet ($4) with ¼ cup shredded cheddar cheese ($4), 1 cup spinach ($4), topped with one avocado ($4)
- 467 Calories: 1 cup of green beans ($4) topped with 1 ounce of shaved almonds ($4) and a large baked sweet potato with butter ($4)
- Total Calories: 1,832. You may need more or fewer calories depending on your age, weight, gender, and activity level.
Evening meal:
- 880 Calories: 300 grams of boneless, skinless chicken breast ($4) with 1 cup of quinoa ($4) and 2 cups of broccoli ($4) sauteed with 2 tbsp of olive oil ($4)
- 350 Calories: Kale salad with butternut squash, edamame, and fuji apple slices ($4)
- 309 Calories: 1 cup of lentil soup ($4) with 1 cup of roasted Brussels sprouts with parmesan ($4)
- 275 Calories: 1 medium banana ($4) with 1/4 cups almonds ($4)
- Total Calories: 1,814. You may need more or fewer calories depending on your age, weight, gender, and activity level.
These examples merely reflect popular breakfast and dinner options, but you can vary the foods as you see fit.
Just remember, while it may be tempting to eat whatever you want on the OMAD diet, it's recommended that you focus on $4 that ensure you're getting enough vitamins and minerals.
The science behind the OMAD diet
Less extreme versions of intermittent fasting that allow a four or eight-hour eating window have been shown to improve $4, increase $4, and aid in $4. Yet, eating one unusually large meal can have the opposite effect of dieting in the first place.
One $4 in the journal Nutrition Reviews from 2015 cautions against extreme versions like the OMAD diet because it can lead to an abnormal increase in appetite and body fat percentage beyond where you were when you started the diet.
"When you eat once a day, you feel weak and sick. When it comes time to eat, one tends to overeat which can lead to a surge of insulin and ultimately feeling unwell," says Melissa Rifkin, a registered dietitian and owner of $4 in New York City.
Who should not try the OMAD diet
Rifkin warns that the OMAD diet can be dangerous to children, elderly, and people with health conditions like $4. These groups need a steady intake of calories to maintain proper health. Also, people who regularly take prescription drugs should steer away from the OMAD diet because most medications require you to eat when taking them.
As for a healthy adult, "it may be safe, but that doesn't mean it is ideal," says Hampton.
Both experts, Hampton and Rifkin, say that there is just not enough research to recommend this diet as a proper $4 technique.
"There are healthier ways for people to eat while reaching their goals. Lean protein, plenty of produce, and quality fats and carbs can provide a broad spectrum of nutrients and can be tailored in a way to meet many different health and wellness goals," says Hampton.
Insider's takeaway
The OMAD diet is a form of intermittent fasting that restricts eating to a one-hour window every day. This means that all your daily calorie needs, depending on your age, weight, gender, and activity level, must be met during this window.
Other than low-calorie or diet beverages, there are no food or drink restrictions.
But dietitians and scientists caution against this type of extreme fasting. They say it can lead to an increase in appetite and overeating, leading to an adverse outcome for those with weight-loss goals. It can also be dangerous for children, elderly, people with certain health conditions, and people who take regular prescription drugs.
Overall, experts say there is not enough research to support recommending the diet for weight loss.