Is Obesity Socially Contagious?

A new study published in the journal Obesity attempts to answer two questions:

  1. Does obesity tend to “cluster” among young adults?
  2. And if true, what impact does the “cluster” have on the weight and weight-related behaviors of it’s members?

The Study

The researchers took 288 volunteers (66% female, 75% Caucasian) and divided them into two groups – Normal Weight (NW) and Over Weight (OW).

Each test subject filled out a questionnaire to determine weight, height, number of overweight social contacts (friends, lovers, relatives, classmates, etc…) and perceived social norms for obesity and obesity related behaviors.

Members of the OW group were also asked to assess how many of their overweight/obese social contacts:

  1. were currently trying to lose weight
  2. were intending to lose weight in the near future
  3. encouraged weight loss in other overweight contacts
  4. would encourage/approve weight loss in their overweight contacts

The Results

Compared to normal weight young adults, those who were overweight or obese were more likely to:

  • have an overweight romantic partner (25 percent  vs. 14 percent for the NW group)
  • have an overweight best friend (24 percent vs. 14 percent for the NW group)

This led the researchers to conclude that obesity is socially contagious.

It also reinforced previous research published in the NEJM.

However, when they considered that…

  1. “both groups reported similarly low levels of social acceptability for being overweight, eating unhealthy foods and being inactive” and
  2. among OW/OB young adults, having more social contacts trying to lose weight was associated with greater intention to lose weight

…the researchers also concluded that “overweight and obese young adults who had more social contacts trying to lose weight were more likely to want to lose weight themselves”.

And to me, that’s the most important part of this study.

While peer pressure and social structure does have the negative effect of ghettoizing overweight individuals into groups, it can also have a powerful effect on changing weight-related behaviors.

And if anyone is interested in developing a successful weight loss program is listening, this is where they should begin.

With positive peer pressure.

Not with food pyramids or calorie counters or lectures on health & longevity, blah, blah, blah.