What do British Prime Minister Rishi Sunak and singer Bruce Springsteen have in common? They are part of a growing group of public figures touting the benefits of eating just one meal a day.
As a result, the one meal a day diet (OMAD) is one of the latest trends in weight loss. Proponents say it leads to rapid long-term weight loss and better health, including delaying the aging process.
Like most weight loss programs, the OMAD diet makes big, bold promises. Here’s what you need to know about eating one meal a day and what it means for your figure.
The OMAD diet explained
The OMAD diet is a type of intermittent fasting, in which you fast for 23 hours and consume all of your daily calories in a single meal, eaten over the course of an hour.
The rules of the OMAD diet are presented as simple and easy to follow:
-You can eat whatever you want, as long as it fits on a standard plate, with no calorie restrictions or nutritional guidelines to follow.
-You can consume calorie-free drinks throughout the day (water, black tea and coffee).
-You should follow a consistent eating schedule, eating your meal at around the same time each day.
In addition to involving a calorie deficit, resulting in weight loss, followers believe that the extended fasting period of the OMAD diet leads to physiological changes in the body that promote better health, including boosting your metabolism by triggering a process called ketosis, in which your body burns stored fat for energy instead of glucose.
What does science say?
Unfortunately, research on the OMAD diet is limited. Most studies have looked at its impact on animals, and the main human study involved 11 young people who followed the OMAD diet for just 11 days.
Claims about the OMAD diet are generally based on research on intermittent fasting, rather than the OMAD diet itself. There is evidence supporting the effectiveness of intermittent fasting for weight loss. However, most studies have focused only on short-term results, usually considering results achieved over 12 weeks or less.
A longer-term study conducted in 2022 randomly assigned 139 obese patients to a low-calorie diet with time-restricted meals between 8:00 a.m. and 4:00 p.m. per day, or to a diet with daily calorie restriction only for 12 months.
After 12 months, both groups had lost about the same amount of weight and experienced similar changes in body fat, blood sugar, cholesterol and blood pressure. This indicates that the long-term weight loss achieved with intermittent fasting is not superior and comparable to that achieved by traditional dietary approaches (daily calorie restriction).
So, what are the problems with the OMAD diet?
1. It can lead to nutritional deficiencies and health problems. The OMAD diet’s lack of nutritional guidance on what to eat for one meal a day raises many red flags. The meals we eat each day should include a protein source balanced with whole grain carbohydrates, vegetables, fruits, protein and good fats to support optimal health, disease prevention and weight management.
Not eating a balanced diet will lead to nutritional deficiencies which can lead to poor immune function, fatigue and decreased bone density, leading to osteoporosis.
Fasting 23 hours a day is also likely to lead to extreme hunger and uncontrollable cravings, which can mean you consistently reach for foods that aren’t good for you when it’s time to eat.
2. It is unlikely to be sustainable.
You may be able to stick with the OMAD diet at first, but it will ease off over time.
Extreme diets – especially those that prescribe prolonged fasting periods – are not enjoyable, leading to feelings of deprivation and social isolation during meals. It’s hard enough to turn down a piece of birthday cake at the office, best case scenario, imagine how you’d feel when you haven’t eaten in 11 p.m.!
Restrictive eating can also lead to an unhealthy relationship with food, making it even more difficult to achieve and maintain a healthy weight.
3. Quick fixes don’t work.
Like other popular intermittent fasting methods, the OMAD diet is attractive because it is easy to implement and provides rapid results.
But the OMAD diet is just another fancy way to cut calories to get a quick drop on the scale.
As your weight decreases, your body activates its defense mechanisms. In fact, it will gain weight again – a response that stems from our hunter-gatherer ancestors’ need to survive periods of deprivation when food was scarce.
This article was written by researcher Nick Fuller and published on the website The Conversation.
