Tacuinum sanitatis, Biblioteca Casanatense 4182 (14th c.)
They should eat foods of little nourishment, great bulk, and quick digestion, and often bathe before they eat… they should eat many vegetables with sharp vinegar dressings… they should exercise frequently and swiftly before eating, and tolerate hunger. They should accustom themselves to eating once a day and sleeping less, and they should drink old and fine wine…. sleeping little and in a hard bed, frequent sex, and spending time in the sun and in warm houses all make a fat body become slender.
Maino de’ Mainieri, Regimen sanitatis
Your medieval summer weight-loss plan: sunbathing, sex, and… salad.