Are we "Socially Contagious"?

Study: Obesity is 'socially contagious'

By ALICIA CHANG, AP Science Writer Wed Jul 25, 11:10 PM ET

If your friends and family get fat, chances are you will too, researchers report in a startling new study that suggests obesity is "socially contagious" and can spread easily from person to person.

The large, federally funded study found that to be true even if your loved ones lived far away. Social ties seemed to play a surprisingly strong role, even more than genes are known to do.

"We were stunned to find that friends who are hundreds of miles away have just as much impact on a person's weight status as friends who are right next door," said co-author James Fowler of the University of California, San Diego.

The study found a person's chances of becoming obese went up 57 percent if a friend did, 40 percent if a sibling did and 37 percent if a spouse did. In the closest friendships, the risk almost tripled.

Researchers think it's more than just people with similar eating and exercise habits hanging out together. Instead, it may be that having relatives and friends who become obese changes one's idea of what is an acceptable weight.

Despite their findings, the researchers said people should not sever their relationships.

"There is a ton of research that suggest that having more friends makes you healthier," Fowler said. "So the last thing that you want to do is get rid of any of your friends."

The study was published in Thursday's New England Journal of Medicine and funded by the National Institute on Aging.

Researchers analyzed medical records of people in the Framingham Heart Study, which has been following the health of residents of that Boston suburb for more than a half century. They tracked records for relatives and friends using contact information that participants provided each time they were examined over a 32-year period.

In all, 12,067 people — all Framingham participants — were involved in the study.

After taking into account natural weight gain and other factors, researchers found the greatest influence occurred among friends and not in people sharing the same genes or living in the same household. Geography and smoking cessation had no effect on obesity risk.

On average, the researchers calculated, when an obese person gained 17 pounds, the corresponding friend put on an extra 5 pounds.

Gender also had a strong influence. In same-sex friendships, a person's obesity risk increased by 71 percent if a friend gained weight. Between brothers, the risk was up by 44 percent and 67 percent between sisters.

Indiana University statistician Stan Wasserman said while the study was clever, it had its limitations because it excluded relationships outside of the Framingham group.

Obesity is a global public health problem. About 1.5 billion adults worldwide are overweight, including more than 400 million who are obese. Two-thirds of Americans are either overweight or obese.

Much of the recent research focus has been on the intense hunt for obesity genes involved in appetite or calorie burning. Treatment has been mainly centered on helping individuals curb their weight through better diet and fitness.

The findings could open a new avenue for treating this worldwide epidemic. The researchers said it might be helpful to treat obese people in groups instead of just the individual.

"Because people are interconnected, their health is interconnected," said lead author Dr. Nicholas Christakis, a Harvard sociologist.

Obesity experts not involved in the research said the results back up what they have suspected all along — that people look toward one another for what is an acceptable weight.

"If you're just a little bit heavy and everyone around you is quite heavier, you will feel good when you look in a mirror," said Dr. David Katz, director of Yale University's Prevention Research Center.

Now you've got me going! No, we are not contagious. I say that the study is one more case of "Much ado about nothing new." Like so many social science studies, this one is full of "maybe," "possibly," etc. It seems to me that it boils to noting that social, cultural--environmental--factors affect behavior (as do genetics) and that over tme norms and expectations change. There is no way to tease out the influence of personal social factors (friendships, relationships) from larger, culture wide ones: changes the amount of physical labor involved in daily living, changes in food, technology, etc. I often feel as if we're suffering from too much anaysis of statistical minutiae. But what really scares me is the possibility (not so remote) of even more Nanny State Big Brother efforts to "treat" groups aka communities. I remain, your cordial skeptic.

Don't know about anyone else, but I was never successful at getting anyone to eat the crap I ate in anywhere near the same quantity.

Just firing at random (better than "not at all"??), but my wife is thin and always bringing home cookies and chocolate.

Dave

Most of my friends have always been of normal weight, so why didn't I impact them. That's all we need is people thinking that they will get fat by hanging around with others who are fat. Maybe the next thing will be that they will start sueing fat friends for making them gain weight. I have to agree with Doug, too much research into nothing important. And the study was probably paid for with our tax dollars. Oh no, I won't even go there.

One of my biggest regrets in life is that I played a huge part in my Ex becomming heavy.  She was a skinny little X-C runner when we met.  Even though I never put anything in her mouth, I still encouraged poor habbits and choices. Scott

Never put anything in her mouth? (hehe... remember, this is the Men's board).

Best Wishes- Dx

...and that's why we are divorced!

Good reason! That should be a requirement put in all marriage vows.

Dave

They should do more research to see if marriage makes most people fat. That would certainly seem to be the case. My own yo-dieting seems to follow a married, fat THEN divorced, thin & fit pattern. It's amazing what people can do/ not do when there's sex involved.

Dave