Are Your Friends Making You Fat?

Many factors contribute to the epidemic of overweight and obesity, but new research suggests that other people’s eating habits could be influencing your food intake more than you realize.

The study, published online by PLoS One, examined the eating habits of 70 pairs of female strangers sharing dinner in a lab setting made to look like a restaurant. The authors observed the meal and assigned codes to each bite taken, noting whether it was within 5 seconds of the other woman’s bite. (“Mimicked bites” were those that were taken within 5 seconds of each other, and “nonmimicked bites” were those taken outside of the 5-second window.) Overall, both women mimicked each other, meaning they were more likely to take a bite along with their eating companion, rather than eat at their own pace. However, the mimicry was more prominent at the beginning of the meal than at the end. The authors hypothesize that the women were trying to be agreeable and make a good first impression, and eating at the same pace puts people at ease.

The authors claim that this type of behavioral mimicry accounts for social modeling associated with food intake. Taken one step further, they hypothesize that surrounding yourself with people who eat a lot will lead you to eat more, and surrounding yourself with people who limit food intake will influence you to eat less. But, the experiment involved only a small sample of a limited demographic. And, it was conducted in a lab setting and involved pairs of strangers. It is impossible to say if these findings translate at all to the real world. Do friends and family have the same influence on eating? Maybe the women were just hungry, so they kept eating. Or, maybe, since they were strangers, they didn’t have anything to talk about at the beginning of the meal.

Social settings and cultural beliefs certainly influence food intake and overall dietary habits, and overweight and obesity does appear to occur within families and social networks. Unhealthy eating habits and low levels of physical activity are influence by friends, as early as childhood, and it makes sense to surround yourself with people who have the same lifestyle habits and interests as you. But, plenty more factors influence our decisions about eating than just the people we eat with.

Is it better to under-eat and be disagreeable or over-eat and make a good first impression? Decide for yourself how much you want to eat and eat that much. If your eating companion doesn’t find you agreeable, so be it.