The size of food portions in depictions of the Last Supper over the centuries

This is pretty rad:

My brother—a religious studies professor at Virginia Wesleyan College—and I indexed the sizes of all of the entrees, loaves of bread, and even plates in the 52 most famous Last Supper paintings from the past millennium featured in Last Supper (2000, Phaiden Press), based on the sizes of people's heads. Through plagues and potato famines, the average size of entrees increased by 69 percent, plates by 65 percent, and bread by 23 percent. (The only thing that didn't continually increase with time was the number of wine bottles on the table—that peaked in the apparently party-happy 16th century.)

The idea is that, since the kind and amount of food during the Last Supper is not specified anywhere, artists would insert whatever seemed natural to them in their culture and time period. So this would reflect humanity's growing bread basket...