(Clarification/update: Some have read this post and missed the fact that it is a joke. It is, indeed, a joke.)
Michelle Legro in Lapham's Quarterly on the culinary-themed writings, sketches, and opinions of Leonardo da Vinci, who was known as "fat boy" when he was a pastry-snarfing 17-year-old kitchen apprentice.
Five hundred years before Modernist Cuisine’s exhaustive look at molecular gastronomy, The Kitchen Notebooks of Leonardo da Vinci envisioned a culinary world as studio and laboratory, where food was to be prepared efficiently, beautifully, and ingeniously. Unfortunately, Italian food of the late fifteenth century had less to do with the luxurious feats of Ancient Rome and more to do with the rustic tastes of the Goths, whose dishes included meats and birds for those who could afford it, and an endless parade of porridge and gruel for those who could not. Leonardo was horrified by much of the food that was served to him, both at court and at home, and he included in his notebooks a running list of dishes that he hated, but that is own servant insisted on serving him: jellied goat, hemp bread, white mosquito pudding, inedible turnips, and eel balls—which he notes, “this dish if eaten often can cause madness.”
The notebooks, which include a history of Leonardo’s tenure as chef at the Sforza court, is primarily a collection of recipes (cabbage jam, snail soup), wayward thoughts (“Would porridge balls in gold-leaf attract My Lord’s attention?”), dining etiquette (“On the Unseemly Behaviors at My Lord’s Table”), household tips, (“On Ridding your Kitchens of Pestilential Flies”), and household inventions (“The Machines I Have Yet to Design for my Kitchen”).
And from da Vinci's writings on table etiquette, it sounds like people back then were real slobs:
He should not place his head upon his plate to eat.
Neither should he sit beneath the table for any length of time.
He should not place unpleasing or half-chewed pieces of his own food upon his neighbor’s plate without first asking him.
He should not wipe his knife upon his neighbor’s clothing.
Nor use his knife to carve upon the table...
He should not set loose birds upon the table.
Not snakes nor beetles...
And if he is to vomit then he leaves the table.
Likewise if he is to urinate.
Did you know that late in life, da Vinci became a vegetarian? Alta Cucina notes that the book reveals this, and that it was "A really strange decision and condemnable lifestyle in Renaissance Italy, where meats were largely consumed."
You can buy the book here.