In 2007 researchers from Harvard looked at data from the Framingham Study, which followed the population of Framingham Mass for more than 35 years and were able to reconstruct familial and social networks within the town's population. Their findings were very impressive. In short, if you are close to people who are obese either by relationship, family, or proximity you had a higher likelihood of becoming overweight or obese yourself. As with all things in life the more we get accustomed to certain things the less out of the ordinary they seem. For instance, when I was a kid growing up Natalie on Facts of Life was the overweight girl, today she does not seem particularly overweight as everyone else has gotten quite a bit bigger as well over the past 30 years so my baseline point of reference has changed. What used to seem obese to me is now mildly overweight and I have a new baseline for what obesity is.
What does Facts of Life have to do with my weight today. Well according to the study the more people you have in your life that are overweight you are more comfortable with your weight being slightly higher than it should be and slowly over time every one's baselines shift upward. Here is where the concept of an Obesity Epidemic becomes real. As more people gain weight and develop social networks, which is even easier to do today, more people will be exposed and more people will be more comfortable with their increasing weights. Over time, people will be more comfortable with their extra 5 or 10 pounds and so will the people in their close network. You can see how over 30 years this would spread through a population.
Fortunately, the study also showed that for people who were losing weight, and I imagine exercising, their behaviour was also contagious in that their cohort lost weight, were in better condition, and likely had better health. However, so few people were in this group that the researchers could not make any firm conclusions. It does make sense to me though that the inverse of the contagiousness of obesity would be the contagiousness of diesel. The more fit and healthy you are, the more fit and healthy your network will be. The more you do, the more your, mom, your brother and your college roommate will do as well. As a community physician I routinely talk about my own exercise program, admit to failings in diet, and encourage people to do the same in their peer groups. I think with this simple exercise we can all imagine making a positive impact on our own communitys' health.
