The link between fast food and obesity is no secret. People who eat it regularly are more likely to be overweight. And when researchers compare neighborhoods, states or whole nations, the ones with more fast-food outlets tend to have higher rates of obesity. It stands to reason that obesity rates might rise and fall along with fast-food sales, and that policymakers could slow the epidemic by constraining the fast food industry.
Health advocates have long believed that, and new research suggests they’re onto something.
In a study published by the World Health Organization on Monday, researchers in the United States and Ireland analyzed fast-food sales in 25 high-income countries from 1999 to 2008. Per-capita purchases increased in all 25 countries during that period. So did the average person’s body-mass index (BMI), a measure of weight in relation to height.
But the countries in the study varied widely. And as the researchers predicted, those with the biggest increases in fast-food sales also experienced the most weight gain.
Between 1999 and 2008, the annual number of fast-food purchases increased buy just 1.5 per person in Italy, and the country’s average BMI rose by a modest 0.3%. In Australia, the annual number of purchases jumped by 15 per person over the same period, and the average BMI increased by 0.9%—three times more Italy’s. As a rule, the study found, every 1% increase in a country’s fast-food purchases yielded a .03% increase in its body-mass index.
As the study makes clear, there’s a reason that some countries—notably Australia, New Zealand, Ireland and Canada, as well as the United States and the United Kingdom—have experienced fast-food explosions while others (France, Italy, Belgium, Greece and the Netherlands) have seen smaller increases in fast-food consumption and obesity. Simply put, the hardest-hit countries have done the least to promote healthy, sustainable food systems.
Does public policy really affect people’s diets and health risks? To find out, the researchers ranked all 25 countries on the so-called Index of Economic Freedom, a scoring system developed by the Heritage Foundation and the Wall Street Journal to celebrate countries that impose few restrictions on commerce and industry. “In line with previous research,” the researchers write, “our study shows that countries adopting what are considered market-liberal policies experience faster increases in both fast food consumption and mean BMI.”









