According to 2nd-century CE physician Galen, everyone was born with a predominance of one of Four Humours, which governed a person’s Temperament: Sanguine (prone to optimism), Choleric (anger), Melancholic (depression), or Phlegmatic (lethargy). One’s Temperament could be affected by particular foods, also divided into four types: sweet, bitter, sour, and salty.

Diet was therefore key to a person’s well-being, and people were advised to refrain from eating foods of the same Humour as themselves.

Phlegmatics were advised to avoid ‘watery’ food like fish and waterfowl, unless ‘corrected’ with hot and dry substances, like spices, garlic, salt, and even sugar.