How to Lose Weight, c. 1330

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.

How to Dye Your Hair Blonde, 1650

Nicolas Arnoult, Recueil des modes de la cour de France (1687), LACMA

"How to make ones haire to become of a yellow Golden Colour. Take the rinde, or outward parings of Rhubarbe, and put them to steep in Whitewine, or clear Lye; wet a spunge or linnen cloth therein, and  anoint your haire therewith, and let them dry before the fire or sunne; the oftener you do this the sooner they will become yellow: note that before you use this, it is good to clear your head and hair from sweat, and all other filth whatsoever." 

A Brief Collection of Many Rare Secrets

Your new summer hair look: golden color, rhubarb flavor, and no filth whatsoever.