How Japan's '80%' philosophy of eating may help us all be healthier
It's not about losing weight, though that may be a byproduct.
Many Americans were told to "clean your plate" growing up, meaning to eat everything you were served at mealtime. To leave food on your plate was considered rude, ungrateful or otherwise undesirable behavior, and the habit of eating everything in front of you became ingrained.
Kids raised in Japan may have been brought up with an entirely different philosophy, one that tells them to stop eating before they are full. It's called hara hachi bu (or sometimes hara hachi bun me).
Stop eating when you're 80% full
Hara hachi bu literally translates to "belly 80% full" and on it's face that's literally what it means—stop eating when your stomach feels 80% full. Asako Miyashita, RDN, a New York-based dietitian who grew up in Japan, told Women's Health that the phrase comes from a 300-year-old book by Japanese philosopher and botanist Ekiken Kaibara, "Yojokun: Life Lessons From A Samurai." The book is about listening to your body, and its author lived to 83, which was a remarkably long life at a time when the life expectancy in Japan was 50.
Fast forward to today, and the people of Okinawa, Japan, where hara hachi bu is a popular phrase, have some of the longest life expectancies on Earth. But can eating only until you're 80% full actually help you live longer?
It's possible. One reason may be calorie restriction. According to longevity researcher Dan Buettner, Okinawans eat about 1,900 calories per day on average. Compare that to Americans who eat over 3,500 calories per day on average. Caloric restriction has been shown to increase the lifespan of multiple animal species and has also been shown to slow the aging process in healthy human adults, so simply not pushing our caloric intake by filling our bellies all the way full may be something to consider if we're looking to live a long life.
Hara hachi bu encouraged mindful eating
Another benefit of the 80% full idea is that it forces you to be mindful about how your body's feeling while you're eating, which may contribute to better physical health. According to Harvard University, mindless or distracted eating—the opposite of mindful eating—is associated with anxiety, overeating, and weight gain.
"Hara hachi bu is not a diet, but a lifestyle that can help promote a sustainable approach to eating," dietician Kouka Webb, RN, told Women's Health. "It encourages mindful eating and portion control without the need for strict calorie counting or eliminating certain food groups."
A family eats dinner in Japan.Photo credit: Canva
Harvard shares that a literature review of 68 intervention and observational studies found that mindfulness and mindful eating slowed down the pace of people's eating and improved people's recognition of when they were full. Mindful eating also reduced binge eating and emotional eating.
Overeating can lead to weight gain, of course, but it can also disrupt your hunger regulation, increase your risk for certain types of disease, cause stomach issues like nausea, gas and bloating, and can even impair your brain function. If you stop eating when you're 80% full means you're far less likely to overeat.
But does that mean you're always left 20% hungry? Not necessarily. According to the Cleveland Clinic, it takes up to 30 minutes for your brain to actually process that your stomach is full, so if you stop when you feel 80% full, you'll most likely feel 100% full just a short while later.
Eat until you're not hungry, not until you're full
“There’s a huge gap between being physically satisfied and realizing in your mind that you’re full,” psychologist Susan Albers, PsyD. tells the Cleveland Clinic. “The connection between them is more like old-school dialup speed than instantaneous WiFi.”
Eating to 80% full is probably closer to the "eat until you're no longer hungry" advice that she gives her patients to feel satiated without actually feeling "full."
“When we think about the word ‘full,’ it’s often like filling up a cup or occupying every inch of a space,” Dr. Albers says. “But the fullness that we can feel and perceive in our stomachs is often being overly full. ‘Satiated’ is different, though. Satiated is meeting a need.”
As Buettner writes, "There is a significant calorie gap between when an American says, ‘I’m full’ and an Okinawan says, ‘I’m no longer hungry.’"
Of course, the traditional Japanese diet also tends to be quite healthy in terms of what they eat, but mindful eating, paying attention to how your stomach feels and stopping before getting full, is worth applying no matter what cuisine you're eating. Next time you sit down for a meal, give hara hachi bu a try and see how you feel. It definitely can't hurt.