The number of cases of obesity is increasing in recent decades. It even calls this epidemic disease.
Several explanations have been proposed to elucidate this phenomenon, including societal changes that encourage lack of physical inactivity as well as overeating. Because genetics can not explain the occurrence of obesity in such a short period of time, the physical and social environments remain among the most likely causes.
A recent study published in the scientific journal The New England Journal of Medicine concludes that obesity is contagious! But beware, this has nothing to do with bacteria or viruses. Obesity would rather be “socially contagious.” That is to say that the weight gain in our family or our friends would increase our risk to gain weight.
Obesity, family and friends
The authors analyzed 32 years of data gathered from collections in more than 12,000 study participants’ Framingham Heart Study. ” The weight and size of these individuals were measured every 2 to 4 years, and for calculating their body mass index (BMI). To determine the social network of the study participants, in addition to the list of the spouses and family members, they were to give each business the name of close friends. In this way more than 70% of the individuals named in the lists themselves have been included in the study.
With the availability of this huge social network, the results of this unique study in the world of medical sociology have shown that body weight is not only a personal responsibility. People who are dear to us would have a significant impact on our waistlines.
Indeed, from these results, the risk that a person becoming obese increases by 57% if a friend becomes obese himself. Even two and three degrees of separation from friends (friends of our friends, friends of friends of friends), the risk of obesity increases by 20% and 10% respectively.
On the side of the family, the risk of obesity increases by 40% in the presence of a brother or sister becomes obese. In the case of married couples, if one of the two individuals became obese the other sees his chances of becoming obese increase by 37%.
Moreover, the results show that people of the same sex have much more influence on each other (female friendships / wife, brother / brother, etc.) than those of the opposite sex. This would explain that same-sex friends have more influence each other as spouses to each other.
Geographic distance seems to have little importance in the presence of friendship and strong family ties. Indeed, the results show that the risk of a person becoming obese are influenced by family members and friends, even if they are geographically distant. For cons, the immediate neighborhood does not seem to have any influence. Thus, it seems unlikely that local environmental factors are responsible for the observed weight gain.
How to explain these results?
It is difficult to answer this question. We do not know how obesity can spread in the social network. However, the authors have made some explanations for this social phenomenon:
Individuals choose to “associate” with like.
Individuals share common attributes or recent experiences that result in changes in weight at the same time.
Individuals have a social impact on their families….