Hara hachi bun me (腹八分目) (also spelled hara hachi bu, and sometimes misspelled hari hachi bu) is a Confucian[1] teaching that instructs people to eat until they are 80 percent full.[2] The Japanese phrase translates to "Eat until you are eight parts (out of ten) full",[2] or "belly 80 percent full".[3] There is evidence that following this practice leads to a lower body mass index and increased longevity, and it might even help to prevent dementia in the elderly.