In the Okinawa diet, a traditional Japanese way of eating emphasizing plant-based, whole foods, many people embrace the philosophy of “hara hachi bu,” the concept of eating until you’re 80 percent full.
Growing up, your parents may have taught you that not finishing your food was against the rules—however, it may actually benefit your health to leave a portion, experts say.
Although hara hachi bu has been practiced for hundreds of years within Japanese culture, it gained popularity in August 2023 when the docu-series Live to 100: Secrets of the Blue Zones debuted on Netflix. The show follows author and explorer Dan Buettner on a trip to the world’s “Blue Zones” where people live longer than average—including Japan, which has the highest number of centenarians (people who live to be 100 or older) in the world.
There, he witnessed locals practicing “hara hachi bu” at mealtime. “This idea teaches each Japanese generation that our portion size is small,” says Asako Miyashita, RDN, a New York-based dietitian who grew up in Japan. In Live to 100, it is believed that this cultural practice may be part of the reason that Okinawa has such a high percentage of centenarians.
To break it down, “hara hachi bu” directly translates in Japanese to “belly 80 percent full,” or eating until you’re 80 percent full, says Kouka Webb, RN, a New York-based dietitian born and raised on “hara hachi bu” in Japan. Although the idea was born over 300 years ago, it is still a common saying in Japan today, Webb says.
As Buettner learned from traveling to Okinawa, many older residents say the phrase “hara hachi bu” out loud before they eat a meal—a ritual Miyashita says her family did during her childhood. The phrase serves as both a pre-meal blessing and a reminder to stop eating before you are too full.
Benefits Of The “Hara Hachi Bu” Approach:
You might enjoy meals more. Rather than following a strict diet plan that makes you cut out foods you love, you can continue to enjoy your favorite treats, just at a healthier pace (and without feeling overstuffed).
It can work as a long-term weight loss strategy, however, that’s not its intended purpose. “Hara hachi bu” is not a diet, but a lifestyle that can help promote a sustainable approach to eating, says Webb. “It encourages mindful eating and portion control without the need for strict calorie counting or eliminating certain food groups,” she adds.
It may help your body digest food better. Overeating can cause indigestion and stomach pain, per Cleveland Clinic. When you eat until you’re 100 percent full (and beyond that), you slow down digestion, absorption, and metabolism, Miyashita says. “This puts strain on organs such as the stomach, intestines, pancreas, kidneys, and liver,” she says.
“By eating until 80 percent full, people may experience less discomfort and reduce strain on the digestive system,” Webb says. “Eating until you’re 80 percent full is associated with a lower risk of acid reflux, bloating, and gastrointestinal issues.” Hara hachi bu can also help to regulate blood sugar levels, Webb adds.
It can help you eat more mindfully. “‘Hara hachi bu’ can help distinguish between physical hunger and emotional eating,” Webb says. “Mindful eating can reduce stress and improve an overall sense of well-being.” Feeling satisfied rather than overly full can reduce negative feelings and promote a more positive relationship with food, Webb adds.
It may lower your risk of chronic diseases. Okinawans have far fewer age-related illnesses like diabetes, heart disease, and cancer, according to a 2024 study on longevity in Okinawa. Among Okinawans who follow a traditional Japanese diet (including hara hachi bu), the incidence of prostate, colon, and breast cancers is about 50% lower than the rest of Japan, per a 2009 study in the Journal of the American College of Nutrition.