What would Jesus eat? Probably a lot less than we do now, according to an examination of how portion sizes have changed over time. Two brothers with divergent interests—Brian Wansink, a marketing professor and director of the Food and Brand Lab at Cornell University's department of applied economics and management, and Craig Wansink, professor and chair of the department of religious studies at Virginia Wesleyan College in Norfolk—collaborated to examine artistic depictions of the Last Supper over the years to see how portion sizes have changed.
Not surprisingly, they found that relative sizes of the entree, bread, and plates have increased during the past 1,000 years. In order to control for the dimensions of different works of art, the Wansinks indexed average size of food items to the average size of the heads of human subjects. (Head size hasn't changed over that time, while average height and weight have.) They found that the relative size of the main course increased by 69.2 percent, the relative size of the bread by 23.1 percent, and the plate by 65.6 percent.
The Wansinks say versions of the Last Supper very likely offer an accurate peephole into portion size because the attention of the artist was on religious themes. "Whether it was an artist working in 1200 or 1600, the main focus is probably not what's on the table," says Brian Wansink. So, he says, the size of the food and plates is what the artist thinks is appropriate "given the time and context in which he lives." The research is published in the International Journal of Obesity.
The project began with a discussion sparked by Leonardo da Vinci's 15th-century mural depicting the meal. "My interests are pretty theological," says Craig Wansink. "But Brian started looking at all the mundane things," he says. In the da Vinci version, it appears the food on the table includes eels and orange slices. "We started wondering, 'Wow, what's going on in other paintings?' " says Craig. They ended up analyzing 52 of the most artistically significant depictions of the period from 1000 to 2000, though Craig says the period of artwork considered basically ended in about 1900. (There haven't been many significant, non-parodic Last Suppers created since then.) But the trend pointed upward, suggesting a painting done today would reflect our supersize portions.
Brian Wansink has turned to history to track portion sizes before. Last year he published research in the Annals of Internal Medicine showing that recipes in Joy of Cooking have seen their calorie counts per serving increase over successive editions—a full 63 percent in 70 years. Would other cultural works, say literature or movies, be appropriate points of reference for analyzing portion sizes? It depends, he says. The food has to be incidental, not the emphasis of the work. "It can't be Babette's Feast," he says.