Obesity Could Be Socially Contagious Say Researchers
[Medical News Today]
Researchers from the UK and Belgium suggested obesity could be a socially contagious phenomenon, after they found that people were influenced by the weight of those around them, such that their view of how overweight they were, and the decisions they made about dieting, depended on how they compared themselves with others of the same age and gender.
The study is the work of economists at the University of Warwick and Dartmouth College in the UK, and the University of Leuven in Belgium and is being presented this week in Cambridge, Massachusetts,USA, at the National Bureau of Economic Research (NBER) Summer conference on Health Economics.
Co-author of the study, Professor Andrew Oswald of the University of Warwick, said:
"Consumption of calories has gone up but that does not tell us why people are eating more."
The researchers sourced data on 27,000 people in 29 European countries from a number of surveys, including the Eurobarometer, the German Socioeconomic Panel (GSOEP), the UK's National Child Development Study, the British Cohort Study and the Health Survey of England. The Eurobarometer is a regular survey carried out for the European Commission and currently covers 29 countries.
The results showed that nearly half of European women and less than a third of European men feel overweight.
The researchers found that men and women are subconsciously influenced by the weight of people around them. Without realizing it, people are caught in a spiral of "imitative obesity", as they try to "keep up with the Joneses". A person's weight relative to others even affects job promotions and selection of partners.
The more educated Europeans are the toughest on themselves. No matter what their BMI (Body Mass Index), a person with a university degree views is considerably more likely to see themselves as fat than a person with lower educational qualifications.
The researchers use an expression called "utility", an economic term that roughly equates to levels of satisfaction. They concluded that a person's utility depends on their own weight relative to the weight of others around them, leading to the suggestion that it is easier to be fat in a fat society.
But there were significant differences between men and women, said the researchers. European women were much more likely to feel overweight, regardless of their BMI. Among females, dissatisfaction with weight and perception of being overweight was linked not only to their actual BMI, but also to their BMI relative to other women of the same in the same country.
On the other hand, for men, being overweight was not important if they were among men who were also overweight.
Oswald said that some people argue that the obesity epidemic is a result of cheaper food, but if that were the case, then the rich should be fatter than the poor, and routinely we observe that is not the case.
"A lot of research into obesity, which has emphasized sedentary lifestyles or human biology or fast- food, has missed the key point," said Oswald.
"Rising obesity needs to be thought of as a sociological phenomenon not a physiological one, he added, observing that, " people are influenced by relative comparisons, and norms have changed and are still changing."
Oswald and colleagues concluded that:
"Although our results should be viewed cautiously, and fixed-effects estimates are not always well-determined, there are some grounds to take seriously the possibility of socially contagious obesity."
"Imitative Obesity and Relative Utility."
David G. Blanchflower, Andrew J. Oswald, and Bert Van Landeghem.
Prepared for the NBER Summer Institute on Health Economics, July 25, 2008.
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