The One Meal A Day Diet (OMAD Diet) – How It Works, Health Benefits, And Safety

Reviewed by Merlin Annie Raj, Registered Dietitian
by Charushila Biswas
ISSA Certified Specialist in Fitness & Nutrition

If the traditional 5-6 meals per day diet is not helping you lose weight, you must try the one meal a day diet (OMAD diet). This intermittent fasting is an extended form of the 8-hour diet. You will fast for 23 hours, and have an hour to eat healthy without restrictions. Scientists at the University of California studied the effect of fasting on humans and found that people who fast have low cholesterol and blood sugar levels, improved gut microbiota, and active metabolism (1).

So, fasting every alternate day or twice a week can not only help you lose weight but also improve your health. This article is a beginner’s guide to the one meal a day diet that explains how it can work for you, what to eat in the one hour window, foods to avoid, and the dos and don’ts. Let’s begin!

What Is The One Meal A Day Diet?


The one meal a day or OMAD diet, as the name suggests, requires the dieters to consume one meal per day instead of three meals and two-three snacks in a day. This, in turn, restricts the calories you consume throughout the day. As a result, you will lose weight, won’t feel bogged down, and your digestion improves. All you are required to do is consume nutritious foods during the one hour window and fast the other 23 hours.

Most dieters eat during dinner time, but you can eat according to your convenience and preference. In some cases, dieters may be allowed to drink green tea (0 cals) or black coffee (3 cals) and have a few solid foods like an egg or an apple during the day. This is done for the safety of the dieter and since each body responds differently to the same diet plan.

So, why do we recommend this seemingly extreme diet? Find out next.

How Does The One Meal A Day Diet Work?

The one meal a day diet works on the principle of calorie restriction and consuming nutritious and low-calorie food one time of the day (or night). When you fast for 23 hours, your body will use the energy reserve (fat) as fuel. Taking the readily available energy in the form of carbs, fruit sugar, etc. aids fat mobilization. It also prevents constipation and improves digestion and absorption, thereby positively influencing fat loss.

However, the one hour window that you get can become your enemy if you don’t watch what you eat. Here’s a list of foods that you can consume.

Foods To Eat On OMAD Diet


  • Veggies – Carrot, broccoli, cabbage, cauliflower, beetroot, turnip, scallions, purple cabbage, Chinese cabbage, lettuce, bell peppers, sweet potato, white potato with peel, spinach, and kale.
  • Fruits High GI fruits like grapes,watermelon, mangoes, and pineapple, and canned fruits should be consumed in limited amounts.
  • Protein Chicken breast, lean cuts of pork and beef, fish, mushroom, beans and legumes, tofu, and eggs.
  • Dairy Full-fat milk, full-fat yogurt, cheddar cheese, feta cheese, buttermilk, homemade ricotta cheese, and cottage cheese.
  • Whole Grains Brown rice, black rice, broken wheat, millet, quinoa, barley, and sorghum.
  • Fats & Oils Olive oil, rice bran oil, sunflower butter, peanut butter, edible grade coconut oil, and almond butter.
  • Nuts & Seeds Almond, walnut, pecan, pine nuts, pistachios, macadamia, sunflower seeds, pumpkin seeds, and melon seeds.
  • Herbs & Spices Cilantro, mint, dill, fennel, rosemary, thyme, oregano, garlic, ginger, onion, coriander, cumin, turmeric, cayenne pepper, black pepper, white pepper, chili flakes, allspice, star anise, cardamom, garlic powder, and clove.
  • Beverages Water, homemade lemonade, homemade electrolyte, coconut water, freshly pressed fruit juice, and cold pressed juices.

So, you see, you have a lot of options to choose from and make delicious food at home with minimum fuss. However, you should be aware of what you should avoid to maintain your health. Here’s a list of foods you must avoid.

Foods To Avoid On OMAD Diet


Fruits – High GI fruits like grapes, jackfruit, mangoes, and pineapple should be consumed in limited amounts.

Protein Fatty cuts of pork and beef and bacon.

Dairy – Low-fat milk, low-fat yogurt, flavored yogurt, and cream cheese.

Whole Grains White rice. Consume in limited quantities and include at least five types of veggies with it to balance out the GI.

Fats & Oils Hemp seed oil, dalda, lard, vegetable oil, butter, margarine, and mayonnaise.

Nuts & Seeds Cashew nuts

Processed Foods Salami, sausages, fries, ranch dip, bottled jams, and jellies.

Beverages – Packaged fruit and vegetable juices, soda, diet soda, and energy drinks.

Now that you know what you should eat and avoid, let me tell you how to design your meal so that you don’t lose focus while on the OMAD diet. Scroll down.

What To Include In Your One Meal A Day Diet 

  • Include at least five types of veggies.
  • Consume three types of fruits.
  • Include lean protein sources in your diet. However, once in a while, you can consume a controlled portion of red meat.
  • If you are a vegetarian, consume a good amount of plant protein such as nuts, seeds, kidney beans, garbanzo beans, and whole pulses.
  • Consume half a bowl of curd or a cup of buttermilk to aid digestion.
  • Have a few unsalted nuts. Make sure not to go overboard with them.
  • You can consume a piece of 80% dark chocolate.
  • For other sweet treats, choose fruits and sour cream or yogurt. Or bake and store brownies that contain healthy ingredients and, of course, less sugar.
  • Keep yourself hydrated throughout the fasting phase.
  • You can drink 3-4 cups of green tea during the fasting phase.
  • If you workout, make sure you consume an egg before working out and replenish your electrolyte reserve by drinking coconut water post-workout.

Speaking of workout, do you need to workout while you are on the OMAD diet? Find out in the next section.

Should You Workout While On The OMAD Diet? 

  • Initially, when you fast for such a long duration, you will not have the energy to workout. Plus, mental fatigue will not allow you to put in the effort required for your workout. Do stretching exercises or yoga to keep your muscles active.
  • When you get used to this intermittent fasting, you can slowly include muscle toning workouts to prevent sagging of your skin.
  • However, always consult your trainer to design a workout that works for you, keeping your medical condition and body type in mind.
  • Whether you are on the OMAD diet or not, practice meditation every day. You can do it the traditional way or while taking a walk or running.

Why should you even choose OMAD diet over any other diet? Let’s find out.

Benefits Of The One Meal A Day Diet


  • Aids Weight Loss

Scientists believe that modified versions of intermittent fasting can help you lose weight by improving sleep patterns and aiding proper digestion (2).

  • Improves Health Markers Of Type II Diabetes

Obesity, genetics, and an unhealthy lifestyle are the main causes of type II diabetes. Researchers found that patients with type II diabetes who followed intermittent fasting were able to lose weight, had reduced calorie intake, and lower glucose and insulin levels post meals (3).

As intermittent fasting has shown to improve insulin sensitivity, people with a BMI over 25, type 2 diabetes, or prediabetes (who are not on medications for lowering blood sugar) may try it.

  • Helps Protect The Heart

The best part of intermittent fasting is that it helps reduce visceral fat and lowers LDL (bad) cholesterol, which, in turn, improves heart health (4).

  • Prevents Weight Regain

This is what sets intermittent fasting and the OMAD diet apart from every other diet. Of course, weight loss is a journey with a lot of ups and downs. But if you manage to go on the OMAD diet twice a week, you will be less likely regain the lost weight (5).

  • Energizes You

Yes, intermittent fasting will keep you energized throughout the day. The main reason for this is that as you get rid of the inflammation-inducing fat deposits, your body starts working better. This, in turn, helps keep your cells active and lowers your fatigue levels.

  • Does Not Deprive You

When you are on the OMAD diet, you will not feel deprived. You will have a filling, nutritious, and delicious meal that will keep your junk food addiction at bay. Of course, you have to follow a “foods to avoid” list so that you don’t put your heart, liver, and kidneys at risk.

It is clear that the OMAD diet can actually work for you. However, before you start, here are a few things you should keep in mind.

Risks Of Following The One Meal A Day Diet

  • It is not easy for a first timer. You will feel hungry and restless.
  • You might feel weak.
  • You might feel dizzy and experience brain fog.
  • You will not be able to concentrate properly.
  • Metabolism in menopausal women may slow down.


Since our bodies respond differently to diets, you must talk to your doctor or a registered dietitian before you start following the OMAD diet. Moreover, pregnant and lactating women should not try this diet.

To conclude, the OMAD diet is a refreshing and effective diet that is result-oriented and prevents weight regain. Nothing better than a diet that helps you maintain the lost weight! So, talk to your doctor today, restock your refrigerator and kitchen cabinets with nutritious foods, and take the first step toward improving your health. No more thinking. Get started! Good luck!

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Charushila Biswas

Charushila Biswas is a Senior Content Writer and an ISSA Certified Fitness Nutritionist. She is an alumni of VIT University, Vellore and has worked on transgenic wheat as a part of her Masters dissertation from NRCPB (IARI), New Delhi. After completing her Masters, she developed a passion for nutrition and fitness, which are closely related to human psychology. And that prompted her to author a review article in 2015. She has written over 200 articles on Fitness and Nutrition. In her leisure time, Charushila loves to cook and enjoys mobile photography.