From the medieval anatomists who used food to restore the balance of the body and the early Islamic philosopher Avicenna who observed that ‘mental excitement or emotion’ hinders digestion, from Jewish holy days like Yom Kippur in which fasting helps the devout to enter the right state of mind to atone, to the fifteenth-century monks who used fermented milk to quell anger and the private physicians who urged their patients to forgo rich meals in favour of even temperament, dietary advice often addressed itself to the emotions as well as to the stomach.
