(Press-News.org) TEMPE, Ariz. – Obesity is socially contagious, according to research published in the past few years. How it is "caught" from others remains a murky area. But findings from Arizona State University researchers published online May 5 in the American Journal of Public Health shed light on the transmission of obesity among friends and family.
Shared ideas about acceptable weight or body size play only a minor role in spreading obesity among friends, according to the findings published in the article "Shared Norms and Their Explanation for the Social Clustering of Obesity."
"Interventions targeted at changing ideas about appropriate body mass indexes or body sizes may be less useful than those working more directly with behaviors, for example, by changing eating habits or transforming opportunities for and constraints on dietary intake," wrote lead author Daniel J. Hruschka, and co-authors Amber Wutich, Alexandra Brewis and Benjamin Morin, all with ASU's School of Human Evolution and Social Change.
Hruschka and Wutich are cultural anthropologists, while Brewis is a biological anthropologist, and Morin is a graduate student in applied mathematics for the life and social sciences.
"When you see that something like obesity spreads among close friends and family members, this raises important questions about how it's spreading. Is it because we learn ideas about acceptable body size from our friends and family members, or that we hike together, watch TV together or go out to eat together?" said Hruschka.
"If we can figure out exactly why obesity spreads among friends and family members, that can tell us where to focus resources in curbing rates of obesity. Is it more effective to change people's ideals of acceptable body size in hopes that they will change their behaviors or rather directly target socially shared behaviors that can contribute to weight gain or loss?"
To dig deeper into how clustering of body attitudes account for the observed social contagion of obesity in past studies, the ASU team interviewed 101 women from the Phoenix area and 812 of their closest friends and family members.
Comparing the body mass index (BMI) of the women, their friends and family members, the researchers confirmed prior findings that the risk of a woman's obesity rose if her social network was obese.
But the team also examined three potential pathways by which shared ideals of acceptable body size might cause obesity and body size to spread through social ties.
Hruschka explained: "You might learn what is an acceptable body size from your friends and then change your diet and exercise to try to achieve that. Or, you might not agree with what your friends or family members think, but still feel pressure from them to achieve some ideal body size. Finally, you may form an idea of appropriate body size by simply observing your friends' bodies, which in turn changes your eating and exercise habits."
The team discovered no evidence for the first and second pathways as means of transmission and found only limited support for the third, suggesting that other factors such as eating and exercising together may be more important in causing friends to gain and lose weight together.
A strength of the study was the range of approaches taken to assess body size ideals, including ideal body size, anti-obesity preference and anti-fat stigma. For example, the participants were asked to choose whether they would rather be obese or have one of 12 socially stigmatized conditions, such as alcoholism or herpes. In many cases, the women would rather have more of the other conditions, with 25.4 percent preferring severe depression and 14.5 percent preferring total blindness over obesity.
While this study provides some clues, the authors noted that more work needs to be done to assess how other proposed factors, such as shared activities or other kinds of social norms, account for the relationship between social proximity and similarity in BMI.
"This study is important because it shows that while the clustering of people with larger or smaller bodies is real, it is not shared values between friends that accounts for it," said Brewis, director of the Center for Global Health in ASU's College of Liberal Arts and Science. "This gives us important clues about the best ways to tackle obesity as a public health issue; we need to focus on what people do together, rather than what people think."
###
ARIZONA STATE UNIVERSITY (www.asu.edu)
College of Liberal Arts and Sciences (http://clas.asu.edu)
School of Human Evolution and Social Change (http://shesc.asu.edu)
Tempe, Arizona USA
END
OAKLAND, Calif., May 5, 2011-- Parental exposure to bisphenol A (BPA) during pregnancy is associated with decreased birth weight of offspring, compared with offspring from families without parental BPA exposure in the workplace, according to Kaiser Permanente researchers.
The observational study is published in the current online issue Reproductive Toxicology.
Researchers explained that there was a greater magnitude of decrease in birth weight in children whose mothers were directly exposed to high BPA levels in the workplace during pregnancy, followed by those whose ...
Transformative changes in markets, policy and science, rather than just incremental changes in farming practices and technology, will be critical if the United States is to achieve long-term sustainability in agriculture, according to a nationwide team of agriculturists that includes a University of California, Davis, animal scientist.
The team's recommendations, first published as a 2010 report by the U.S. National Research Council, appear as a Policy Forum piece in the May 6 issue of the journal Science. Lead author on the paper is John Reganold, Regents Professor of ...
Tests of a new antibody-based "biosensor" developed by researchers at the Virginia Institute of Marine Science show that it can detect marine pollutants like oil much faster and more cheaply than current technologies. The device is small and sturdy enough to be used from a boat.
Testing of the biosensor in the Elizabeth River and Yorktown Creek, which both drain into lower Chesapeake Bay, shows that the instrument can process samples in less than 10 minutes, detect pollutants at levels as low as just a few parts per billion, and do so at a cost of just pennies per sample. ...
The Hand and Wrist Institute, the leading hand specialist experts in the State of California now offers a "Where Does It Hurt" tool on their website, www.handandwristinstitute.com.
The Hand and Wrist Institute is a medical center that focuses primarily on the surgery of hands and wrists. This institute is backed by Dr. John T. Knight, one of the top medical experts in the field of hand and wrist surgery. Dr. John T. Knight is a board certified Orthopedic Surgeon who oversees the operations of the Hand and Wrist Institute at DISC to ensure that all of their ...
Scientists from the Walter and Eliza Hall Institute and the University of Melbourne have used innovative new technologies to identify the gene responsible for a rare but fatal hereditary brain disorder. The discovery will make it possible to diagnose the disease through a blood test rather than a brain biopsy.
Dr Melanie Bahlo, Ms Katherine Smith and Ms Catherine Bromhead from the Walter and Eliza Hall Institute's Bioinformatics division, in collaboration with neurologist and epilepsy specialist Professor Sam Berkovic and Dr Todor Arsov from the University of Melbourne, ...
The Psychological Care and Healing Treatment Center, the leading destination for people who want to have their psychological disorders fixed, now offers Panic Disorder treatment Clinic.
A Panic Disorder is considered as such when a person experiences several panic attacks within a short period of time. First of all, people must know that panic attacks are not very common. In fact, some people live their lives and experience only as little as two or three panic attacks through out their lives. This is why it is very uncommon to experience or suffer from several panic ...
French researchers have reported the strongest proof yet that evidence of 'circulating tumor cells' found in samples of a patient's blood is strongly linked to poor outcomes such as a short time to disease progression.
At the IMPAKT Breast Cancer Conference in Brussels, Dr François-Clement Bidard and colleagues from Institut Curie in Paris say their new findings set the scene for interventional trials designed to see if improved outcomes can be achieved by modifying treatment based on circulating tumor cell counts.
"We needed to do this study to confirm data provided ...
The most comprehensive analysis yet of the epigenetic modifications present in breast cancer has revealed potentially important new ways to detect and treat the disease, Belgian researchers have reported.
Epigenetics is a term used to describe modifications to the DNA molecule that affect way its code is translated into proteins. These changes include methylation, a form of chemical modification.
Although researchers knew epigenetics was important in cancer, information about its exact contribution to breast carcinogenesis was scant, Dr Sarah Dedeurwaerder, from Université ...
German researchers have identified an unexpected molecular marker that predicts how sensitive hard-to-treat triple-negative breast cancers are to chemotherapy.
Triple-negative breast cancers --which do not express the genes for estrogen receptor, or progesterone receptor and do not have Her2/neu overexpression or amplification-- are more aggressive than other forms of the disease and cannot be treated with endocrine or Her2 targeted therapies.
At the IMPAKT Breast Cancer Conference in Brussels, PhD student Carolin Huelsewig and Dr Cornelia Liedtke from Uniklinikum Muenster ...
Two multi-gene tests designed to predict the risk of disease progression and response to chemotherapy in breast cancer produce broadly similar results for high- and low-risk patients, but do not always agree in their predictions for those at intermediate risk, a new analysis shows.
In recent years, several genomic tests have been developed to provide prognostic information for breast cancer. Dr Catherine Kelly from Mater Misericordiae University Hospital, Dublin, Ireland, and colleagues in the USA examined the agreement in prediction results between two multi-gene assays ...
