OMAD, or “One Meal A Day,” has become a rather trendy diet approach, especially among weight loss gurus who claim OMAD to be something akin to a magic pill. With celebrities like Bruce Springsteen and even UK’s prime minister Rishi Sunak swearing by this trendy eating approach, you may be wondering if OMAD is something for you.
But as with most extreme diet approaches, eating one meal a day is not a magic fix. In fact, it may bring more harm than good or even swing you in the exact opposite direction of a healthy, balanced lifestyle. We spoke with nutrition experts who are weighing in on this diet trend.
How Does the OMAD Diet Work?
In a nutshell, the OMAD diet is an intermittent fasting regimen that involves a 23-hour fast followed by a 1-hour eating window. This means eating one meal a day, followed by another 23-hour fast.
This single meal should, theoretically, include all the required calories and nutrients you would need for optimal health (meaning, at least 1500 to 2000 calories for most people).
Julianna Szatmari, MS, RDN and the CEO of Intuitively Nourished LLC, stresses the downside of the OMAD diet approach. “While proponents of this diet assert its efficacy, it’s worth noting that this weight loss approach places considerable stress and pressure on the body. In essence, the body must work twice as hard in the limited mealtime, putting strain on the heart and digestive system,” she says.
Compared to more complex diets like keto or paleo, though, the OMAD diet doesn’t restrict the types of foods you consume but only restricts the meal time.
What Happens to Your Body if You Only Eat One Meal a Day?
Most benefits and side effects of eating one meal a day are related to the prolonged fasting period itself. On one side, it may have some benefits to blood sugar, but the same goes for side effects.
“When we eat, our pancreas produces insulin, which triggers glucose uptake for energy production. If we skip meals, our blood sugar levels drop, causing an increase in another hormone, glucagon, which triggers the release of stored sugar, as glycogen for short term energy. People who only eat one meal per day are at higher risk of experiencing hypoglycemia long-term. After eating a large meal, people are at higher risk of experiencing hyperglycemia. This can eventually lead to insulin resistance and development of type 2 diabetes, among other health issues,” explained Carmelita Lombera, RDN, a registered dietitian and nutrition consultant for Consumer Health Digest.
On the other hand, eating once a day can affect blood sugar positively. “Only eating one meal a day will lower insulin response the rest of the day. But of course, what is eaten at that one meal is important. Both quality and quantity of food need to be taken into consideration,” says Kimberly Gomer MS, RD/LDN.
Prolonged fasting can have some other effects, though. Dan Jackowiak, Nc, HHP, and the Founder of Yeast Infection Advisor, highlights the following: “During prolonged periods without food, the body can enter a state of ketosis and begin burning stored fat for energy. Interestingly, if you suffer from gut issues such as leaky gut, these fasting periods can also provide time for the gut to rest and repair its functions, leading to less intense symptoms when digesting food.”
Why Is It Bad if You Only Eat Once a Day?
Most experts agree on one thing: eating one meal a day is not sustainable nor sufficient for most people since it’s hard to cover all of your daily nutritional requirements with one meal.
Carmelita Lombera stressed that most Americans don’t consume enough fiber even right now, so getting all nutrients in one meal may not be realistic. Limiting your nutrition intake for longer periods may lead to malnutrition and even some more serious health concerns.
“It may also be difficult mentally to only eat once a day with a tendency to overeat because of the fear of knowing there’s only one opportunity. In any person with an eating disorder, it is not recommended as it can lead them down a very unhealthy path,” highlighted Kimberly Gomer.
Eating your entire day’s calories and nutrients in one meal is tough in any case, however. The human body needs a rather big amount of food on a daily basis: around 70 grams of protein, at least 25 grams of fiber, over 300 grams of carbohydrates, and a plethora of different vitamins and minerals.
Even protein alone could mean, for example, consuming at least 8 ounces of chicken breast in one sitting. For most people, it’s not viable to have an entire day’s calories and nutrients in one sitting, at least not without feeling stuffed and sick after the meal.
Is There a Healthy Way to Eat Once a Day?
Despite the downsides and troubles eating one meal a day could bring, Kimberly Gomer still believes the OMAD diet could be doable and works great for some people.
“The key is that it comes organically, not forced. So, the person eats a large, satiating meal once/day and is not hungry the rest of the day or night. This generally happens on a completely unprocessed meal plan that includes low carbohydrate, high meat/fat food choices. It can be extremely convenient for some individual’s schedules, assist with weight loss, and increase energy and clarity,” she explains.
For most people and their daily schedule, however, the OMAD diet doesn’t work well. “I would say it is not feasible to stick to in the long run. Most lifestyles do not permit a super healthy way of doing this because people are active and busy. It could also take a toll on one’s mental health and even lead to obsessive behavior around food because OMAD is such a harsh restriction. Intermittent fasting of only eating during one eight-hour window of the day is much more feasible,” recommends Dan Jackowiak.
“While reducing food intake to lose weight may appear tempting to some, a more effective solution and frankly, healthier is to simply seek balance and prioritize mealtimes. Consistently eating three balanced meals throughout the day, which include carbohydrates, protein, and fats, can make it easier to regulate calorie intake and avoid overeating. Eating regularly also helps in controlling appetite, increasing satiety, and promoting weight management,” agrees Julianna Szatmari.
Could It Be Considered an Eating Disorder?
As with any diet approach, there’s no solution that works for everyone. Could the OMAD diet lead to an eating disorder? “In some people, especially those using it in a disordered way, not getting in enough calories or nutrition to meet their requirements – yes,” says Kimberly Gomer.
“But again, it is important to emphasize that there is never a one-size-fits-all approach, and eating one meal a day, while it can work for some, can be a horrible idea for others,” she continued.
Eating disorders need to be diagnosed by qualified specialists, and the OMAD diet itself isn’t inherently a sign of disordered eating, but if done for the wrong reasons, it could lead to developing an eating disorder. Therefore, OMAD diet shouldn’t be practiced by everyone and instead, it’s better to opt for a balanced diet that includes several meals per day.
