When did our problem with food portion size really begin? Brothers Brian and Craig Wansink got an interesting idea on how to answer this question. Using imaging technology, they compared 52 paintings in the book Last Supper and found that the meals have gradually increased in size over a long period time—leading to main dishes that are now 70 percent larger and loaves of bread about 23 percent bigger than they were a thousand years ago. (For a standard, the researchers calculated the size of the food relative to the average size of the disciples’ heads.) Plate size has gotten bigger, too, by more than 65 percent —and earlier experiments have shown that bigger plates lead us to inadvertently overeat because they make portions seem smaller.

“Supersizing”—a term that became popular in the mid-1990s and describes the ability of McDonalds’ customers to increase portion sizes—is often considered a modern phenomenon. But “what we see recently may be just a more noticeable part of a very long trend,” said Brian Wansink, a food behavior scientist at Cornell University (Telegraph). As he explains in a write-up of the research:

The last thousand years have witnessed dramatic increases in the production, availability, safety, abundance, and affordability of food. We think that as art imitates life, these changes have been reflected in paintings of history’s most famous dinner.

Craig Wansink, who is a professor of religious studies, says the changes in portion sizes is probably a reflection of culture rather than theology. “There is no religious reason why the meals got bigger. It may be that meals really did grow, or that people just became more interested in food” (BBC News).

The thing is, for some time now researchers have been uncovering links between religiosity and obesity. Back in 1998, sociologist Ken Ferraro found that people were fatter in states in which a larger percent of the population said they were religiously affiliated. And in a follow-up study published in 2006, he found that women who turned to religious media—books, radio, or TV—were 14 percent more likely to be obese than those who didn’t. At the same time, the more often women attended religious services, the less likely they were to be obese. Men were less likely to be obese if they sought counseling and comforting through religious sources (Purdue University).

On the converse, a more recent study by Dr. Donald Lloyd-Jones found that spiritual and religious people—those who frequently attend religious services or pray—are significantly more likely to be obese than those who are nonreligious. The reason? It’s not immediately clear, says Lloyd-Jones: “We don’t really know if there is something about religious participation that leads to obesity, or if it’s the other way around, and that heavier people might seek out religious and spiritual experiences because of things like stigmatization” (heartwire)

Which findings hold up remains to be seen, but we shouldn’t really be surprised to find a link between religiosity and weight, as Matthew Feinstein, a medical student at Northwestern University who worked on the study with Lloyd-Jones, told us:

Perhaps the most likely explanation for the association between religion and obesity is that religious organizations tend to place little emphasis on avoidance of gluttony or overeating, while instead emphasizing avoidance of more clearly defined practices like smoking. In fact, fellowship around festive meals is common in religious communities and may be viewed by pious individuals as a well-deserved treat for all the time and energy they devote to religious activities. Unfortunately, we’re often hurting ourselves more than we are treating ourselves at these meals, which tend to center around fatty and calorie-dense meats, cheeses, starches, and baked goods.