You are what your friends eat

You are what your friends eat

I’m sure you’ve heard the saying that “you are what you eat”. It’s recently become clear that you are also what your friends eat...and how they exercise...and whether they smoke...and so forth. Your social network shapes your lifestyle habits, for better or for worse. 


A Harvard Medical School study of more than 12,000 people over a 32-year time span revealed that:

  • A person’s chances of becoming obese increased by 57% if they had a friend who became obese
  • If one spouse became obese, the likelihood that the other spouse would become obese increased by 37%

These stats are pretty staggering. They suggest that people’s social networks directly influence their behaviors (including what they deem acceptable or unacceptable behaviors). The study went on to observe that “Having obese social contacts might change a person’s tolerance for being obese or might influence his or her adoption of specific behaviors (e.g., smoking, eating, and exercising).” The study did not address other social behaviors, but I suspect that the same attitude of tolerance might extend to other “vices” (e.g., excessive drinking, extramarital affairs) if that's what you're surrounded by. On the contrary, your tolerance of 5 am workouts or meditation circles might increase if "all of the cool kids" (read: your friends) are doing that as well.


Whether we want to admit it or not, we are implicitly and explicitly influenced by our nearest and dearest. 


Interestingly, a few other patterns emerged from the study:

  • A friend’s weight gain mattered more than a family member’s (which suggests that the weight gain is not predominantly genetically mediated)
  • Same sex peers had a larger influence on weight than opposite sex peers (which suggests that we are more impacted by those individuals who mostly closely resemble us)
  • Social distance mattered more than geographical distance. For example, there was no effect when a random neighbor gained weight but there was an effect when a close friend residing in a different state gained weight (which suggests that your physical environment may be less of a factor than your social environment)

This stuff is powerful!


Here’s the thing: obesity is just the external manifestation here. We probably could have tested other health markers (e.g., blood sugar, inflammatory markers, exercise frequency, stress levels) and saw a similar result. Obesity is an output; lifestyle behaviors are the input. The really great thing about this is that we can change our behaviors


The study even acknowledged this important fact, stating that “Network phenomena might be exploited to spread positive health behaviors...in part because people’s perceptions of their own risk of illness may depend on the people around them.” Basically, if social networks can spread negative behaviors, they can also spread positive behaviors. That’s exactly what we see in The Blue Zones (more on that later!). 


One thing I want to mention: please don’t misunderstand the message here. This isn’t about size discrimination. This is about recognizing that your friend’s behaviors rub off on you (whether you consciously realize it or not). Over time, these behaviors impact your health and your happiness. It’s important to simply be conscious of your surroundings and choose wisely to align with the goals that you are trying to achieve in your life.
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