Diet trends are kind of like Kardashians—there’s always at least one making major headlines and taking over our social feeds. One that has gained recent popularity is fasting, which was one of the most Googled diet trends of 2018. Fasting isn’t a new concept, but celebs like Halle Berry, Kourtney Kardashian, Vanessa Hudgens, and Chris Pratt have all brought it into the spotlight by talking about the benefits of intermittent fasting (IF).
IF is more of an eating pattern than a diet because it doesn’t put restrictions on what you can eat but when. Most people who do IF follow a 16:8 rule, where you fast for 16 hours and eat all your calories within the remaining eight hours of the day. The idea is that by restricting the number of hours in which you’re eating, the total number of calories you’re consuming in a day will be reduced. So if you want to eat cake for dinner, it’s technically allowed during your eating hours (but don’t eat cake for dinner for obvious reasons).
Like all things in life, if something shows promise, we’ll find a way to take it to the next level. This is the case with the “One Meal a Day” or OMAD diet, which is basically an extreme version of IF. Here’s everything you need to know about this trending diet.
What is OMAD?
OMAD is exactly what it sounds like—you only eat one meal each day. You follow a 23:1 rule, where you fast for 23 hours and then have one hour of eating per day. Ideally, and for consistency, you eat within the same four-hour timeframe every day, only use one standard dinner plate (no seconds), and the food on your plate can’t be more than three inches high. You are allowed to drink calorie-free beverages throughout the 23 hours of fasting, and you’re free to choose whatever you want to eat during the other hour.
Studies have shown IF to contribute to weight loss and overall health in rats, but the research is less conclusive for humans. Benefits for animals have included reducing the risk of obesity, non-alcoholic fatty liver disease, diabetes, and cancer in rodents. But according to Maggie Moon, MS, RD, and author The MIND Diet, “trying to translate results from captive lab animals into practical eating patterns for humans is challenging.”
“The research shows that just about any kind of IF will result in weight loss, though alternate day fasting [where you alternate between days of no eating and days of normal eating] led to intense hunger on fasting days,” she adds. “That may be one upside to OMAD—at least you get to eat daily. Ultimately, research on IF hasn’t shown superior weight loss compared to standard calorie restriction.” In other words, you may lose weight, but it’s not the only (or necessarily best) way to do it.
A small two-month study showed that subjects following OMAD compared to eating three meals a day had a 4.1 percent weight loss and improvements in blood sugar and cholesterol. However, Moon cautions that there are no long-term studies of either IF or OMAD. “It hasn’t been tested long-term, and doesn’t seem feasible for most lifestyles.”
Imagine how hangry you can get when you skip one meal… now extend that to 96 percent of your day. Eating just one meal of whatever you want may sound more appealing than remembering a list of things you can or can’t eat or tracking every calorie, but you’re more likely to binge and less likely to get all your daily nutrients in that one hour alone. OMAD also requires stricter planning of your day and fewer, say, spontaneous brunches and happy hours.
Moon warns that there are certain types of people who should not try IF and OMAD, such as anyone with a history of disordered eating, growing children who are developing their relationship to food, or pregnant women. Additionally, people with diabetes or those on specialized diets should not attempt fasting without consulting their doctor, as OMAD could interfere with other health monitoring or other prescribed routines.
For those who work out regularly and want to try OMAD, Moon says “while most healthy people can likely survive a moderate workout while eating one meal a day, peak athletic performance is best fueled before and after workouts with the appropriate macro and micronutrients for performance, recovery, and muscle development. Bottom line: You can [try it], but it’s not ideal.”
Healthy living should not be tied to weight loss only, and every body functions differently, so there is no magic bullet that works across the board. “The best healthy eating pattern for any individual is a nutritionally balanced diet that is realistic for that individual to maintain for the long term,” says Moon. Figure out what works for you personally, versus blindly following a schedule set by someone else. “For weight loss, it’s one strategy, but there are easier ways to healthfully lose weight. In addition, there just aren’t enough human randomized clinical trials to convince me to recommend this way of eating over a more reasonable approach.”