Archive for August 20th, 2007

Obesity Can Spread Among Friends….

August 20, 2007

v8chmcaa05ticcak5yizmca823xazcafcorr9cau78ovncabxtl0pcazrko7ecaf2w095ca5k5nuxca5ged70ca3tp5t0ca8cc9bocaouwo3hcazf6mzccauuysvrcahe8nawca7phliscaild0s8.jpgA family with obese children is a pretty common sight.  The family may have the same set of genes but it’s the relationship among family members that count…the way they spend time together or the way they choose the lifestyle from the kind of food to the kind of leisurely activities.  So I always counsel my patients to be extra careful with what they choose to eat or keep in the fridge because those are the choices that their kids will have for the rest of their lives…and they may have devastating outcome!

Now comes a study that proves the social networking not only affect close relatives but also friends….. A recent online publication of the Premier Journal of Medicine: The New England Journal of Medicine July 26, 2007 issue reported the effect of having friends who are obese….


 Methods:  The authors evaluated a densely interconnected social network of 12,067 people assessed repeatedly from 1971 to 2003 as part of the Framingham Heart Study. The body-mass index was available for all subjects. We used longitudinal statistical models to examine whether weight gain in one person was associated with weight gain in his or her friends, siblings, spouse, and neighbors.


  1. A person’s chances of becoming obese increased by 57% (95% confidence interval [CI], 6 to 123) if he or she had a friend who became obese in a given interval.
  2. Among pairs of adult siblings, if one sibling became obese, the chance that the other would become obese increased by 40% (95% CI, 21 to 60).
  3. If one spouse became obese, the likelihood that the other spouse would become obese increased by 37% (95% CI, 7 to 73).
  4. These effects were not seen among neighbors in the immediate geographic location.
  5. Persons of the same sex had relatively greater influence on each other than those of the opposite sex.
  6. The spread of smoking cessation did not account for the spread of obesity in the network.

Conclusions:  Network phenomena appear to be relevant to the biologic and behavioral trait of obesity, and obesity appears to spread through social ties. __________________________________________________________________________________________________

These findings have implications for clinical and public health interventions.  It’s the social networking that really makes a difference…whether the influence is positive or negative.  Teaching kids the right way from the way they choose : the kind of food… to the kind of friends… to the kind of activities… should start from the young!

The authors’ summary of their report says it all: 

The spread of obesity in social networks appears to be a factor in the obesity epidemic. Yet the relevance of social influence also suggests that it may be possible to harness this same force to slow the spread of obesity. Network phenomena might be exploited to spread positive health behaviors, in part because people’s perceptions of their own risk of illness may depend on the people around them.”

As the saying goes….. 

Tell Me Who Your Friends Are…And I’ll Tell You Who You Are!