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.
The one-meal-a-day diet — also known as 23:1 intermittent fasting — may help people lose weight and body fat. However, it can lead to hunger and cravings and may not be suitable for everyone.
Just know this; while you might be hungry, you're definitely not “starving.” Something else that OMAD brings is a sense of getting in touch with your hunger, and how your body feels during fasting. Over time, you'll learn how great you can feel, even without food.
The One Meal a Day diet is a type of fasting. Fasting is defined as abstaining from eating food and calorie-containing beverages for a period of time. There are two mainstream types of intermittent fasting diets––time restricted feeding (TRF) and alternate day fasting (ADF).
2. How long should you stay on the OMAD diet? Nutrition professionals do not advise trying the OMAD diet for any length of time. It's incredibly restrictive and unsustainable and can lead to extreme weight loss, nutrient deficiencies and binging.
OMAD can then start to look a lot like chronic caloric restriction. Although chronic caloric restriction helps with initial weight loss, it poses long-term concerns because it tends to lower resting metabolic rate, which makes weight loss very difficult to maintain.
The 18:6, 20:4, and one-meal-a-day (OMAD) protocols are types of time-restricted eating where you abstain from eating for 18 to 23 hours, and then eat freely for the rest of the day. They can be combined with a caloric deficit for weight loss, but don't have to be.
Risks of OMAD
An unhappy stomach Some people experience cramping or stomach pain with eating after prolonged periods of fasting. Others may have diarrhea or loose stools. Increased blood sugar OMAD fasting has been found by one study to increase fasting glucose (5).
The OMAD eating plan works on the theory that your body can stay within a constant state of burning fat by restricting your calories to one feeding time. Your body uses the calories from eating regular meals and snacks at a steady rate for energy.
Mood swings, lack of concentration, irritability are some common side effects of following one meal a day diet. If you eat fewer calories in a day, your body goes into a preservation mode, which slows down your metabolism. This may be harmful to you in the long term.
Bulimia and your actions
If you experience bulimia, you might: eat lots of food in one go (binge) go through daily cycles of eating, feeling guilty, purging, feeling hungry and eating again.
Yes, you sometimes do feel tired after a meal on OMAD as blood is shunted away from the brain and to the digestive system, but I'd like to point out that nearly everyone feels this way after a meal, especially after a meal of heavily processed fast food.
While it seems perfectly fine to eat two meals a day, such a routine is not suitable for everyone. There are a few groups of people who are advised not to try such a diet plan. It is because such a meal plan may increase their risk of health problems.
You need to eat only once when on OMAD diet, but that doesn't mean that you will not even have water for the rest of the day. Keeping yourself hydrated is the key to lose weight. So, drink plenty of water. You can even have coffee, tea, and other calorie-free beverages when following this diet.
OMAD is a very effective way for losing weight quickly, and with few (if any) negative side effects. In fact, you will likely see a decrease on the scale within the first few days or week of starting this type of intermittent fasting protocol.
Outside of the eating window, there are no restrictions on the OMAD Diet. So you can eat whatever you want on OMAD, as long as it's in your eating window. Now, as in any intermittent fasting protocol (which OMAD would fall into), it's encouraged that you eat as healthy as possible during your eating window.
Although various forms of intermittent fasting 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.
Fasting, as you may have heard, can be hellish. But Varady says most people will adjust within 10 days after starting — and that the same is probably true for OMAD.
What to Eat on the OMAD Diet. The single meal you eat on OMAD may contain anywhere from 1,500 to 2,500 calories or more, depending on your body weight, size, and health goals, says Moskovitz.
Some other major concerns of following OMAD is that this form can cause inadequate calorie consumption/not meeting energy needs, nutrient deficiencies which can lead to malnutrition.
Foods To Avoid On OMAD Diet
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.
If you still want to try the OMAD diet, strive for a wide variety of nutrient-rich foods like fruits, veggies, whole grains, and lean proteins.