Why is the developed world obese?

The rapid increase in body mass index (BMI) over the past few decades means that a growing share of the population in developed countries is becoming obese. This study focuses on understanding why the developed world is becoming so obese. The strong similarities in both level and trend of adult obesity across the developed world suggest similar causes. 

Specifically, the authors find that increased caloric supply accounts for 82 percent of adult obesity in developed countries. Evidence on trends in energy expenditure and caloric supply, as well as results from different methods of energy accounting, suggest that the increasing prevalence of adult obesity in developed countries is primarily attributable to over consumption.

The paper examines two main mechanisms driving increases in caloric supply:

• technological innovations - those factors which reduce the costs associated with consumption and increase opportunities to eat. In particular, relative food prices and the ease of businesses to enter the market place. The authors find lower relative food prices to be associated with increased caloric supply 
• changing sociodemographic factors - the rise of wage opportunities for women for instance has
  increased family income  and suggests that countries with higher female labour force participation have higher levels of caloric consumption. Also, increased urbanisation has been repeatedly tied to reductions in physical activity and increases in caloric intake

The authors then argue that these results suggest that changes in consumption can be addressed through policy intervention, describing the impact that increased food prices would have on caloric supply and food consumption.

Finally the paper concludes that, as developed countries continue to develop and innovate, without interventions the factors driving increased caloric intake identified in this research and elsewhere will likely increase, making it harder and harder for individuals to maintain a healthy weight.

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