Call me conventional, but I prefer to have three regular meals a day. I mean, I guess I can see why someone might feel inclined to consume all of their daily calories at once — finding the time and motivation to eat three times a day can be a challenge sometimes. But then there are those who do it intentionally: The enthusiastic dieters who consume one colossal meal a day for the purpose of losing weight. And I just… no.
This restrictive diet is called the One Meal a Day (OMAD) meal plan, and the concept is that limiting your calories to a single feeding time keeps the body in a constant state of burning fat, similar to how intermittent fasting works. “The One Meal a Day diet is sometimes called the 23:1 diet, because a person spends 23 hours of their day fasting, leaving just one hour of the day to eat, drink and consume calories,” explains nutritionist David Friedman, author of Food Sanity: How to Eat in a World of Fads and Fiction. “There’s no snacking allowed between your daily meal, which forces the body to use fat for fuel.”
Sure, it sounds like a cool way to hack your body and shed some pounds. But according to Friedman, the OMAD diet is also a good way to wither into a sluggish zombie person and gain those pounds right back down the line. “There’s no evidence showing the health benefits of fasting for 23 hours every day,” he emphasizes. “I believe this diet is extremely unhealthy.” As we’re about to learn, it can result in high blood pressure, mental and physical fatigue, weight gain and just about every food-related ailment out there, including diabetes, stroke and heart disease.
On the flip side, Friedman points me toward numerous studies showing the benefits of eating three meals a day, including breakfast, a meal that people tend to skip. “A study by the Endocrine Society shows that obese, insulin-treated type 2 diabetes patients, who eat a big breakfast, an average-size lunch and a small dinner experience more weight loss, less hunger and better diabetes control while using less insulin,” he explains. “In a study of nearly 3,000 people enrolled in the National Weight Control Registry — adults who lost over 30 pounds and kept the weight off for over a year — 78 percent ate breakfast. The people who skipped breakfast, meanwhile, gained their weight back.”
While breakfast is especially important because it breaks the fast we engage in while sleeping, eating throughout the day is equally critical. “Every hour, billions of cells in the body die and get replaced,” Friedman says. “The food you consume is what supplies your organs, bones, muscles and nerves with the vitamins, minerals, amino acids, fats and carbs they require to rebuild and grow. Your body needs a replenishment of its nutrients throughout the day.”
“When you starve your body for 23 hours,” Friedman continues, “it uses fat as fuel to rebuild these cells. Sure, that leads to fat loss, but that’s not synonymous with being healthy. There are some bad side effects from the OMAD diet. In clinical trials, scientists have discovered that subjects who have all of their daily calories from one meal develop higher blood sugar levels and elevated levels of ghrelin, a hormone that increases appetite. Meanwhile, the American Journal of Nutrition found that eating once a day causes an increase in blood pressure and cholesterol. The researchers concluded that eating a single meal daily could put people at higher risk of developing serious conditions, such as diabetes, stroke and heart disease.”
Eating three (or more) separate meals, on the other hand, helps with digestion. “When you spread your meals out throughout the day, your stomach and digestive system don’t have to work as hard,” Friedman says. “When you eat one large meal to make up for this deficit, however, it makes your digestive system work harder to process all that food. This requires the heart to work harder to send extra blood to the gut, which raises blood pressure. This can also increase your risk of getting heartburn.”
Not to mention, starvation-based diets tend to come back to bite you in the gut. “While people on this restrictive OMAD diet will initially lose weight, it’s not very sustainable,” Friedman emphasizes. “In fact, research shows it may even cause you to gain weight in the long run — skipping meals puts your body into a feast or famine survival mode, which makes your cells crave more food. When you eat more, it stores the food as fat. Because of the larger calorie allowance on the OMAD diet, people tend to gorge, which can lead to weight gain over time.”
Perhaps worse, going without food for such long periods of time can seriously mess with your brain. “The human brain runs on glucose, and stores of glucose typically last for just four hours after eating a meal,” Friedman says. “If you go longer than that without eating, it can negatively affect your memory, concentration and job performance.”
When you compare these crappy results to the awesome ones caused by eating several meals a day, having breakfast, lunch and dinner — and maybe a couple snacks, too — is the obvious winner. “During my college training in nutrition, I was taught the healthiest way to eat is to consume five to six small meals throughout the day,” says Friedman. “Eating small portions every few hours has been shown to increase a person’s metabolism and improve their energy levels. Research published by the Journal of the Academy of Nutrition and Dietetics also shows that eating frequent small meals throughout the day is associated with improved diet quality and a lower BMI.” Moreover, studies show that having a couple daily meals can decrease hunger and food intake, which obviously results in weight loss.
Nutrition experts generally recommend keeping individual meals no more than about 700 calories each, which is laughably small, especially when you’re used to heaping portions of meat and carbs. But hey, nobody said staying healthy is easy. On the plus side, if you accidentally skip a meal here and there, you can add a couple hundred extra calories to your next bite.
So slow it down, take a couple breaks from work and make sure you take the time to eat a few times a day. “You’re much better off eating healthy, clean and unprocessed whole-food meals, plural,” Friedman reiterates. Yeah, plural!