Follow the Leader in Healthy Dining (or Not)

When it comes to healthy dining, it seems that the company you keep really does matter.

Obesity can spread through social networks. This observation has been pretty well documented for a while now, but the nature of the relationship between obesity risk and social networks has been understood more as an association than as cause and effect. For example, a person’s social network has been linked to their personal participation in sports. Researchers have seen that unhealthy eating habits may be linked to certain patterns of online social networking.

But much of this has been speculation, based on observational studies.

Now, Mitsuru Shimizu, Katie Johnson, and Brian Wansink have published an elegant experiment to demonstrate how the company you keep can indeed cause more or less healthy eating behaviors. Subjects in their experiment served themselves a lunch of pasta and salad after observing an actress serve herself lunch over multiple occasions. On some occasions, the actress was wearing a so-called “fatsuit,” making her appear to have excess weight that was just shy of obesity (BMI of 29). On others, she appeared to have a BMI of 21.

They also varied how much pasta she served herself, relative to salad. On some occasions, she took mostly pasta. On others, she took mostly salad. You probably know where this is going.

Indeed, when the actress was looking larger, people ate significantly more pasta and consumed many more calories. Likewise, when the actress was taking more pasta, the observers served themselves more pasta and consumed it.

Presumably your mother telling you to clean your plate and have some more could have a similar effect.

We’ll get back to you on that.

Click here to read the study in Appetite and here to read more from NPR. Click here to read an earlier study in the New England Journal of Medicine of how obesity can spread through social

Dinner, photograph © John Walker / flickr

Subscribe by email to follow the accumulating evidence and observations that shape our view of health, obesity, and policy.