Hidden Links to the Obesity Epidemic

Obesity epidemic influenced as much or more by environment than by individual choices

(RxWiki News) Any person who sets their mind to lose weight should be able to do so with a doctor's help. But the path that leads people to be obese is more complex.

A recent study's findings point to collective behavior and social factors playing a bigger part in the increase in obesity than genetics or the individual choices people make.

"Talk to your doctor about healthy weight goals."

Hernán Makse, a physicist at the City College of New York, led the study looking at patterns in geography, food marketing and distribution of obesity.

Using data from the Centers for Disease Control and Prevention and comparing it to food centers with complex calculations, the results of Makse's studies point to environmental factors as potentially outweighing the impact of personal choices in the increase in obesity.

"We found there is a relationship between the prevalence of obesity and the growth of the supermarket economy," Makse said. "While we can't claim causality because we don't know whether obesity is driven by market forces or vice versa, the obesity epidemic can't be solved by focus on individual behavior."

Obesity is regarded by the World Health Organization as a global epidemic along the lines of cancer or diabetes because no strategy to contain the spread of the disease has so far proven effective.

Although past and current preventive measures have focused on changing individuals' behavior because of the contributing factors of higher caloric intake and lack of sufficient physical activity, Makse's findings join a growing body of research that shows strong environmental influences on obesity, including "high susceptibility to social pressure and global economic drivers."

Makse and his colleagues had already put forth the theory that collective behavior is actually a bigger factor than individual lifestyle choices and genetics based on past research, but they wanted to investigate this further by using physics and statistics.

Makse tracked the beginning of the serious climb in obesity to about 1980 using data from the CDC. Using the CDC's county level data from 2004 to 2008, they saw similar percentages of obesity in neighboring communities, which Makse called "obesity clusters."

While Greene County, Ala. was the center of the epidemic, two other 620-mile clusters exist along the Appalachian Mountains and in the lower Mississippi River valley.

Makse then compared these clusters to a set of characteristics: population density, prevalence of adult obesity and diabetes, cancer death rates and economic activity.

What they found were "clustering patterns" of obesity that appeared to result from "collective behavior, which may not merely be the consequence of fluctuations in individual habits."

When they compared the obesity clusters to parts of the food production economy, such as supermarkets, food and beverage stores, restaurants and bars, they found that the higher numbers supermarkets, restaurants and the like corresponded to higher rates of obesity.

"The basic idea is that if a non-communicable disease is spreading like a virus, then environmental factors have to be at work," Makse said. "If only genetics determined obesity, we wouldn't have seen the correlations."

The study, available to the public for free, was published online June 14 in the journal Scientific Reports. The research was funded by Epiwork, ARL and the Israel Science Foundation.

The authors declared no competing interests.

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Review Date: 
June 14, 2012