Several of you shared your thoughts and opinions on last week’s post about a study indicating that your friends may have more of an influence on your weight than you think. Some of you felt that yes, your friends really do have an effect on your weight, but others stated that it’s genetics that has the most influence.
While it might sound like a cop-out, I don’t think there’s a single reason that explains why a person is overweight (or underweight, for that matter). While I agree that genetics and environment play a role, I also believe that behavior does, as well. Behaviors can easily become ingrained. That’s why behavior modification is a key component of most credible and successful weight management programs — and most diabetes education programs, too, for that matter.
But back to last week’s topic for a moment. A commentary in Newsweek came out shortly after the study was published. In the article, the author comments that there is still a lot to learn about the “dynamics of obesity.” For example, Dr. Nicholas Christakis, one of the coauthors of the study, notes that a person’s neighbors seem to have no effect on his weight: If your neighbor gains weight, your risk of also gaining weight doesn’t increase. But that’s somewhat easy to understand, since many people really aren’t all that close with their neighbors. The article’s author also notes that same-sex friendships are more influential on weight than male–female relationships, but the reasons for this aren’t very clear. I guess we should stay tuned.
Look Out for Thin Friends with Big Appetites
A new study recently published online in the Journal of Consumer Research, aptly named “I’ll have What She’s Having: Effects of Social Influence and Body Type on the Food Choices of Others,” also hints that a person’s peers or friends have influence over his weight. The investigators in this study set out to learn how someone’s body size and food choices might affect how much others ate.
Roughly 200 college students were recruited to participate in a study disguised as being about movies. Each student was paired up with someone who they thought was another student but who was actually part of the research team. This partner was thin (a size 0!) but, when paired with randomly selected students, would put on an obesity suit that made her appear to be a size 16 and 180 pounds.
The students watched movies and were given snacks. The research partner was offered the snacks first, serving herself either a small or a large portion, and then the student was offered the snack. Interestingly, most of the students served themselves a portion of food similar in size to the research partner. But what was also interesting was that the amount of food the students ate depended upon the size of their partner: If the partner was thin, the students tended to eat more food. But if the partner was wearing the obesity suit, the students ate less.
This study is an illustration of what is called “anchoring,” or relying on a particular piece of information when making decisions. Here, the students focused on the habits of the research partner; if she took more food, the student took more food. If the partner was heavy (that is to say, wearing the obesity suit), the students tended to cut back on what they ate. But, if the partner was thin and ate a lot, the student tended to eat a lot as well, perhaps thinking, “If she can eat that much and be thin, I can do the same.”
Granted, this is just one study with a fairly small sample size. But this study, along with the one I mentioned last week, seems to point to environment and behavioral factors as influencing body weight. What do you think?