Research by economists at the University of Warwick, Dartmouth College, and the University of Leuven, finds that people are powerfully but subconsciously influenced by the weight of those around them. Without being aware of it, the researchers believe, human beings keep up with the weight of the Joneses. For a whole society, this can lead to a spiral of imitative obesity. The researchers will present their results on Friday July 25th at a National Bureau of Economic Research conference in Cambridge Massachusetts in a paper entitled Imitative Obesity and Relative Utility at the NBER Summer Institute on Health Economics.

Using data on 27,000 Europeans from 29 countries, the researchers find that nearly half of European women feel overweight. Less than a third of males feel overweight.

The authors suggest that whether for reasons of job promotions or finding a mate it is someone’s weight relative to others that matters. They show that overweight perceptions and dieting decisions are influenced by people’s comparisons with others of the same age and gender.

Highly educated Europeans hold themselves to a particularly tough standard, the research shows. For any given level of Body Mass Index (BMI), somebody with a university degree feels much fatter than someone with low educational qualifications.

Overall, the researchers believe that a person’s “utility” (an economic term roughly meaning satisfaction levels) depends on their own weight relative to the weight of those around them. They suggest that it is easier to be fat in a society that is fat.

However, the authors also found a significant gender split. Females were much more prone, for any given BMI value, to feel overweight. For European women, weight dissatisfaction and overweight perceptions depended crucially upon not just their own absolute BMI, but also upon their BMI relative to other women of exactly the same age in their country. Conversely, being overweight tended not to be a significant issue for men if many of those around them were as overweight as they were.

Professor Andrew Oswald at the University of Warwick, one of the researchers, said “Consumption of calories has gone up but that does not tell us why people are eating more. Some have argued that obesity has been produced by cheaper food, but if fatness is a response to greater purchasing power, why do we routinely observe that rich people are thinner than poor people?”

He said: “A lot of research into obesity, which has emphasized sedentary lifestyles or human biology or fast-food, has missed the key point. Rising obesity needs to be thought of as a sociological phenomenon not a physiological one. People are influenced by relative comparisons, and norms have changed and are still changing.”

However, the authors found a significant gender split. Females were much more prone, for any given BMI value, to feel overweight. For European women, weight dissatisfaction and overweight perceptions depended crucially upon not just their own absolute BMI, but also upon their BMI relative to other women of exactly the same age in their country.

Notes for Editors:

The researchers used Eurobarometer data on 29 nations, longitudinal data in a number of sweeps of the German Socioeconomic Panel (GSOEP) along with data from the National Child Development Study and the British Cohort Study from the UK and the Health Survey of England

The full research team were:

Professor Andrew J. Oswald
Department of Economics, University of Warwick
Email: .(JavaScript must be enabled to view this email address)
Telephone: 07876 217717

David G. Blanchflower
Department of Economics, Dartmouth College; University of Stirling; Bank of England; and NBER
Email: .(JavaScript must be enabled to view this email address)
Telephone: 001 603 643 1821 or 001 603 646 2536

Bert Van Landeghem
LICOS Centre for Institutions and Economic Performance & Department of Economics
University of Leuven (KUL)
Email: .(JavaScript must be enabled to view this email address)

For further information please contact:

Peter Dunn, Press and Media Relations Manager,
University of Warwick
Tel: +44 (0)24 76 523708
or +44 (0)7767 655860 email: .(JavaScript must be enabled to view this email address)

PR61 PJD 24th July 2008