I'd take that with a grain of salt. At least the line about the Venus of Millendorf is pure conjecture - we don't have the slightest idea what this statue was meant to represent and what it was used for. Similarly there is little to back up that "ample proportions were viewed as desirable" at Rubens' time, and the idea that "illiterate = likes fat women" is just absurd. It's true though that his wife looked quite different from the nudes he painted: https://upload.wikimedia.org/wikipedia/commons/f/ff/Peter_Paul_Rubens_Peter_Paul_Rubens_-_The_Artist_and_His_First_Wife,_Isabella_Brant,_in_the_Honeysuckle_Bower.jpg