WHY IS THE DEVELOPED WORLD OBESE?
November 19, 2007
Rising obesity in the developed world is primarily the result of consuming more calories, according to the authors of a National Bureau of Economic Research Working Paper. Increased caloric intake accounted for 93 percent of the change in adult obesity from1990 to 2001 (the remainder is attributable to reduced energy expenditure). The increase in caloric intake appears to be driven by technological innovations, such as lower food prices and the ease with which businesses can enter the marketplace, as well as changing sociodemographic characteristics such as increased labor force participation and increased urbanization.
According to the authors:
- Across the developed world, average food prices fell by 12 percent from 1980 to 2002, which corresponded to a higher caloric intake of approximately 38 calories.
- A 10 percent increase in female labor force participation was associated with an increase of approximately 70 calories.
- A 10 percent increase in urbanization was associated with an increase of approximately 113 calories.
The authors point out that a very small net increase in calories may lead to a large increase in obesity, and they predict expected changes in weight based on the associations they observe between caloric supply and the drivers of increased consumption. For example:
- Increasing food prices by 12 percent would be associated with a decrease of 1.5 kilograms (3.4 pounds) for the average 65-kilogram (143-pound) person.
- Similarly, decreasing urbanization by 5 percent would be associated with a decrease of 2.2 kilograms (5 pounds) for the average 65-kilogram person.
Further, to bolster their findings, the authors note that obesity among children and the elderly, two groups that we would not expect to be affected by changes in work-related physical activity, has risen along with adult obesity. In addition, the obesity increase has been remarkably similar across countries, which suggests a worldwide phenomenon.
Source: Linda Gorman, "Why is the Developed World Obese?" NBER Digest, November 2007; Based upon: Sara Bleich, et al, "Why is the Developed World Obese?" Working Paper No. 12954, National Bureau of Economic Research, March 2007.
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