In a long-ranging discussion over beer starting from the five acceptable sexual positions according to Albertus Magnus, we got into why "a tergo"* was acceptable -- because a more natural sexual position might be prevented by such problems as extreme obesity.
When I protested that I couldn't imagine being so fat that a tergo was the only possible position, my colleagues brought up images of morbidly obese people who had to be hauled out of their apartments in cranes, etc. To this I responded that I didn't think it was possible for people to get that fat in the Middle Ages. Even if you could afford an unlimited amount of rich foods, you still had to walk everywhere to get around.
This leads me to wonder -- how fat could you get in the Middle Ages? I tried figuring out fat Louis the Fat was, but I can't find anyone who might have figured out how much he weighed. Does anyone know how fat folks like Thomas Aquinas, Henry VIII, and Loius the Fat actually got? Also, as a bonus question, were they too fat for anything in the sack besides a tergo?
*Doggy-style, for those in the peanut gallery.