" Hara hachi bu is a Confucian principle, popular in Japan since medieval times, that you should eat until you are only eight-tenths full. This principle has since been given backing by nutrition scientists who note that when we eat there is a time delay between the body receiving the food and the brain registering that we are full. When the urge comes to have a second helping, it’s worth waiting twenty minutes, and the feeling may pass. "

― Bee Wilson, , First Bite: How We Learn to Eat