Practices of world’s longest-living people: is it healthier to eat until you’re 80% full?
By Cynthia Lodite, November 22, 2025Some of the world’s healthiest and longest-living people follow the practice of hara hachi bu, an eating philosophy rooted in moderation.
This practice comes from a Japanese Confucian teaching that instructs people to only eat until they’re around 80% full.
In research by Aisling Pigott, who is a lecturer of dietetics at Cardiff Metropolitan University, in her contribution to The Conversation, she explains the concept of hara hachi bu and its contribution to weight loss.
“More recently, it’s been gaining attention as a strategy for weight loss. But while hara hachi bu might emphasize eating in moderation and stopping before you’re full, it shouldn’t really be seen as a method of dietary restriction.
Rather, it represents a way of eating that can help us learn to have awareness and gratitude while slowing down at mealtimes,” she said.
On the other hand, research on hara hachi bu is limited; however, previous studies have evaluated the overall dietary patterns of those living in regions where this eating philosophy is more commonplace, not the “80% rule” in isolation.
However, the available evidence does suggest hara hachi bu can reduce total daily calorie intake. It’s also associated with lower long-term weight gain and lower average body mass index (BMI).
“The practice also aligns with healthier meal-pattern choices in men, with participants choosing to eat more vegetables at mealtimes and fewer grains when following hara hachi bu,” she explains.
Her research shows both approaches can also help reduce emotional eating and enhance overall diet quality, also adding that Hara hachi bu may also have many advantages that go beyond losing weight.
Hara hachi bu principles
“Hara hachi bu” also shares many similar principles with the concepts of mindful eating or intuitive eating. These non-diet, awareness-based approaches encourage a stronger connection with internal hunger and satiety cues. Research shows both approaches can also help reduce emotional eating and enhance overall diet quality,” she added.
“For instance, hara hachi bu‘s focus on awareness and eating intuitively may offer a gentle and sustainable way of supporting long-term health changes. Sustainable health changes are far easier to maintain in the long term.
This may improve health and prevent weight regain, which can be a risk for those who lose weight through traditional diet approaches,” she explains.
The ethos of hara hachi bu also makes perfect sense in the context of modern life and may help us develop a better relationship with the food we eat.
Evidence suggests that around 70% of adults and children use digital devices while eating. This behaviour has been linked to higher calorie intake, lower fruit and vegetable intake, and a greater incidence of disordered eating behaviours, including restriction, binge eating, and overeating.
“As a dietitian, I see it all the time. We put food on a pedestal, obsess over it, talk about it, and post about it—but so often, we don’t actually enjoy it. We’ve lost that sense of connection and appreciation,” she noted.
She also argues that being more aware of the food we eat and taking time to taste, enjoy, and truly experience it, as hara hachi bu emphasises, can allow us to reconnect with our bodies, support digestion, and make more nourishing food choices.