Intermittent fasting was one of the biggest diet trends that provided people with an ironclad solution for weight loss in 2018. To round out the year, another form of intermittent fasting is being introduced to the mainstream: the OMAD diet.
OMAD stands for “one meal a day” and that is the gist of the diet. The OMAD diet involves someone eating only one meal daily — during a specific one hour period of the day — and then fasting the other 23 hours. Consistent with other forms of intermittent fasting, fasters are “allowed” to drink black coffee or other non-calorie beverages during their fasting time — but nothing else, according to Women’s Health.
On OMAD, participants are instructed to eat their one meal during the same four-hour window every day, says Jen Oikarinen, a clinical dietitian with Banner University Medical Center Phoenix, to Women’s Health. “Consistency is emphasized in the OMAD diet,” she explains.
That said, there are four specific guidelines that dieters are to follow to be successful on OMAD, known as the “four ones,” Oikarinen explains:
• You should only be eating one meal per day
• You can only eat within one hour of your four-hour eating window
• You must eat off an 11-inch diameter plate
• Your meal shouldn’t be more than three inches high on your plate
Sure, OMAD eating seems like an eating free-for-all that allows you to eat whatever you want while still losing weight — which is what weight loss dreams are made of — but you should strive to make your one meal balanced and micronutrient rich for the sake of your overall health. You only have one chance per day to knock it out of the nutritional ballpark, so you want to get in as much nutrient-dense food as possible, Healthline states.
Obviously, OMAD is essentially a starvation diet — therefore making it very different from many other forms of intermittent fasting — and is not for everyone. Because you’re not consuming as many calories with just one meal as you would by eating eating three or four times a day, weight loss is inevitable. Plus, this nearly constant calorie-deficit will free long-term dieters from meticulously logging foods, according to Healthline.
But other than the weight loss, OMAD can also result in mood swings, muscle loss, hormone disturbances, and even changes in your menstrual cycle (like having it stop completely), says Oikarinen. “Another major concern is the increased risk for nutrient deficiencies; decreased intake of food also means decreased intake of beneficial vitamins and minerals,” Oikarinen explains.
As a result, OMAD is a very controversial diet. Rebecca Elbaum, R.D., clinical administrative dietitian at Montefiore Medical Center in New York, believes not even healthy people should try the OMAD diet. Anyone who’s pregnant, breastfeeding, recovering from past disordered eating, has diabetes, or even regularly exercises or lifts weights should avoid this controversial diet, she says.
Unless you’re a person that often experiments with diets in a safe and healthy manner, the OMAD diet is best avoided. However, if you’re looking to benefit from the weight loss that comes along with intermittent fasting, there’s plenty of information on more approachable forms of fasting here.