Sharing a Snack

Getting a Handle on the Social Environment for Obesity

The idea that obesity is contagious is a “brilliant analogy,” says a distinguished professor of pediatrics, Leonard Epstein. More and more research supports this view. But the ideas about contagion require careful thinking in this context. Thinking about transmitting obesity from one person to another is not especially helpful. What’s more relevant is thinking about the social environment. And a new study in Social Science and Medicine uses sophisticated spatial analysis techniques to add more insight.

Obesity Prevalence That Spreads Across a Region

Massimiliano Agovino and colleagues use Spatial Markov Chains to look for geographic proximity effects in obesity rates. Are regional patterns in obesity – such as we see in the southern states – more than mere coincidence? And indeed they are.

Proximity effects, say these researchers, play an important role in the way that obesity spreads through clusters of nearby states. Obesity rates in an adjacent state can make a very real difference in they way that another state’s obesity rates change over time. Southern U.S. states “may suffer from a perverse ‘geographical lock-in’ effect that calls for coordinated action,” they say.

Taking a Broader View of the Food Environment

Don't Go 'Round HungryIt’s easy enough to see the environment for physical activity in terms of a geographic context. Much research documents the importance of the built environment for routine physical activity levels.

However, when people think about the “toxic food environment” contributing to obesity, much of that thinking typically focuses upon the food itself. What is the composition of macronutrients? How much sugar, salt, and fat? Is it ultra-processed? Does it have “supernormal appetitive properties“?

But perhaps we should pay more attention to cultural factors that influence eating behaviors. Media and food marketing play a role. However, they are only a part of the larger food culture. It’s not hard to see that expectations for how you will feed yourself are different in the deep south or New Orleans than they are in Manhattan or Seattle. Likewise, the food culture of north central states like Wisconsin is very distinct. And obesity rates are high.

Understanding these factors and how to reshape them will not be easy. But without a deeper understanding of shared cultural environments, coping with the social transmission of obesity will be even harder.

Click here for the study by Agovino et al. You can find more relevant research and commentary here, here, here, and here.

Sharing a Snack, photograph © Andy Morffew / flickr

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November 30, 2018

4 Responses to “Getting a Handle on the Social Environment for Obesity”

  1. November 30, 2018 at 9:01 am, Mary-Jo said:

    Some good ecological studies, nationally and internationally, would be great to help elucidate which factors seem to promote or prevent obesity — similar to studies done to identify the Blue Zones in the world and factors associated with longevity and overall health, but looking specifically at obesity outcomes.

  2. November 30, 2018 at 10:58 am, Richard Atkinson said:

    Another explanation for “contagious obesity” is the well documented effect of adenovirus 36 in causing obesity, at least in animals, and an association in humans (it isn’t possible to experimentally infect humans and watch them increase adiposity). About 30% of humans with obesity worldwide have been infected with Adv36, potentially explaining about half of the dramatic increase in obesity from 1980 to 2000. Postulating social factors as the etiology of obesity is full of suppositions, but if infection causes obesity, few suppositions are needed.

    • November 30, 2018 at 12:06 pm, Ted said:

      Good point and I’m glad you raised it, Dick.

  3. November 30, 2018 at 1:05 pm, Harry Minot said:

    Glad to see Dr. Atkinson’s comment. The AD-36 virus has received little attention. It deserves greater consideration.!po=70.2381