Many people feel a little pudgy around the holidays. "Thanks a lot, peanut butter brownies and short-rib pierogis," you may be thinking, as you feel your jeans stretch taut against the pressure of your new thigh fat. But a new study from a team led by Roberto De Vogli at the University of Michigan suggests that the real culprit for your rotundity may be too complicated to be contained on a dinner plate. It suggests that the real cause of high obesity rates is the free market.
In other words, countries that have business-friendly regulations and low tariffs have a higher incidence of obesity than countries with more tightly regulated economies. De Vogli pointed specifically to the U.S., Australia, Canada, New Zealand and the UK as countries with capitalistic economies and high rates of obesity. He also noted that Norway, Japan and Switzerland all subsidize small farmers heavily and have relatively thin populations.
But is this coincidence or cause and effect?
"Correlation doesn't mean causation," De Vogli told The Huffington Post. "But it seems clear that there is a pattern here."
The study began more modestly, looking at the correlation between obesity rates and countries' per capita Subway restaurants. This correlation is extremely strong, even after adjusting for economic and demographic factors.
De Vogli was quick to note, though, that he wasn't trying to single out Subway as a cause of obesity. "There is no particular reason to think that Subway is the culprit here. We were just looking at Subway as a proxy for fast-food restaurants," he said. "There are even studies showing that Subway is relatively healthier compared to other fast-food companies -- although it seems a little ridiculous to call any fast food 'healthy.'"
De Vogli admitted that using Subway as a proxy for the entire fast-food industry introduced its own kind of bias, specifically because Subway might have gone to English-speaking countries like Australia and Canada before some others because of the language barrier.
"Of course, these five countries are at the forefront of the spread of these fast-food companies because of that," he said. "But they are also at the forefront of big business-friendly policies."
His team initially had wanted to use data on McDonald's, but the company refused their request to release data on global locations. Subway had two advantages: it recently became the world's largest chain in number of outlets, and all of its locations are listed for public viewing on the company's website.
The data produced by the analysis are undoubtedly striking. To quote the paper, which is published in this month's Critical Public Health:
Countries with the highest density of Subway restaurants such as the U.S. (7.52 per 100,000) and Canada (7.43 per 100,000) tend also to have a higher prevalence of obesity in both men (31.3 percent and 23.2 percent respectively) and women (33.2 percent and 22.9 percent, respectively). On the other hand, countries with a relatively low density of Subway restaurants such as Japan (0.13 per 100,000) and Norway (0.19 per 100,000) have a lower prevalence of obesity in both men (2.9 percent and 6.4 percent respectively) and women (3.3 percent and 5.9 percent respectively).
Given the holes in the study, it's hard to make any definitive claims about the study's conclusions. It's possible that Japan and Norway are just huge Denny's consumers, and so maintain their litheness despite eating far more fast food than their Canadian and Australian peers. And it's also possible that there's some third factor (besides free market economics) driving both Subway and obesity in these five Anglophone countries. De Vogli said that he's working on another study that he hopes will connect the global reduction of tariff rates with the commensurate global rise in obesity levels, which may help unlock new parts of the puzzle.
But if the exact margins of the takeaway are, at least for now, a little vague, De Vogli says that the policy implications of the study are not.
"It's simple: you tax junk foods and you subsidize fruits, vegetables and healthy foods," he said. "People need to have options, but if they're in an environment where most of the options are unhealthy options, then they don't have many choices."