A study published in the Bulletin of the World Health Organization has  reported “a strong and positive association between fast food consumption and age-standardized mean BMI [body mass index]” in high-income countries, citing market deregulation as a possible factor in increased fast food consumption. Roberto De Vogli, et al., “The influence of market deregulation on fast food consumption and body mass index: a cross-national time series analysis, Bulletin of the World Health Organization, February 2014. In addition to analyzing data on fast food consumption and age-standardized BMI from 25 high-income countries, researchers apparently used the index of economic freedom (IEF) created by the Heritage Foundation and the Wall Street Journal to gauge the extent of market deregulation policies adopted by each country.

According to the results, the average number of annual fast food transac- tions per capita increased from 26.61 to 32.76 between 1999 and 2008, while age-standardized mean BMI increased from 25.8 to 26.4 kg/m2. The study also noted that “market deregulation is a strong predictor of higher fast food consumption,” with each 1-unit increase in the IEF associated with (i) an increase of 0.2715 in the average number of per capita annual transac- tions at fast food outlets and (ii) an increase of 0.0232 kg/m2 in BMI. At the same time, however, researchers recommended further study to determine why the intake of animal fats and total caloric intake did not appear “to be significant mediators of the association” between fast food consumption and BMI, suggesting that subsequent studies focus on “the metabolic effects of long-term exposure to fast foods produced from the meat of animals fed on corn, kept in confinement and exposed to excessive fertilization,” among other things. 

“Our study provides novel findings on the association between fast food consumption and mean population BMI and on the influence of market deregulation as a contributor to higher fast food consumption and BMI,” conclude the study’s authors. “In particular, they suggest that government regulations hindering the spread of fast food consumption might help to mitigate the obesity epidemic. Indeed, although all countries included in our sample have experienced increases in fast food consumption and mean BMI over the period studied (1999–2008), nations that have adopted more stringent market regulations have experienced slower increases in both. More research is needed to confirm whether deregulation is a significant contributor to body weight and to determine what types of government interventions could mitigate the obesity epidemic and curb the spread of transnational fast food companies.”