Researchers have found that, like the flu and sexually transmitted diseases, obesity may be considered as contagious, capable of spreading between family, friends, and neighbors living in close proximity with each other.

However, while obesity is contagious, this does not mean that people who are gaining weight excessively should do nothing but blame the people around them.

Obesity Is Contagious: Here's What That Means

A new study claimed that obesity is a contagious disease, but not in the same way as other illnesses such as the flu.

The researchers, from the University of Southern California and the think tank Rand Corp., confirmed that obesity is a social contagion, through quasi-experimental evidence acquired from the study that involves thousands of military families.

The theory that obesity is socially contagious is based on observations by Yale's Dr. Nicholas Christakis and UC San Diego's James Fowler, who found that certain behaviors and conditions apparently propagate within social networks. In addition to obesity, other social contagions include smoking, divorce, and happiness.

Obesity was identified as one of the very first social contagions, supported by the findings of a 2007 study that if a person becomes obese over a certain period of time, that person's spouse, sibling, or friend saw his or her chance of becoming obese too increase by 37 percent to 57 percent.

Following up on that study, the researchers wanted to check if living in a community with high obesity rates will also increase the risk of gaining weight. The researchers decided to pull in data from another study that focused on the nutrition and exercise habits of teenagers living in military bases, which are known to be tight-knit communities and exactly the kind of environment where social contagions may thrive.

The study, which was published in the JAMA Pediatrics journal, discovered that parents and children who lived in locations with higher obesity rates had higher chances of becoming overweight or obese. For example, in a community where people often have fast food for dinner, or where people rarely walk or exercise, it is more than likely that new members will pick up these practices and start putting on weight themselves.

Don't Blame Your Neighbors For Your Waistline

However, despite the evidence that obesity is a social contagion, this does not mean that people should just blame their neighbors if they are obese or overweight.

While genetics may play a role in the obesity problem, there are many ways for people to start losing weight, even if everyone else is not doing them. These include healthy diets, and apparently, cinnamon. There is also a new anti-obesity drug being developed, but it will take a while before that is made available to the public.