We previously blogged about how children are more likely to eat more when dining with friends who consume more calories, based on a study of teens and tweens published in the American Journal of Clinical Nutrition. In the same vein, there is further research that shows obesity can be contagious.
In a 2007 study spanning 32 years of a social network of 12,000 adults conducted by Harvard researcher Nicholas Christakis and fellow colleagues, it was found that a person is 37 percent more likely to be obese if a spouse is, 40 percent more likely if a sibling is and 57 percent more likely if a friend is.
The reasoning behind these facts is that adults eat more in the presence of family and friends than with strangers, and that socializing with overweight individuals can affect their perceptions of what the norm is regarding eating habits.
Finally, there's the idea that we just like to hang with people that are like ourselves. Cornell food sociologist Jeffrey Sobal explains that "especially among two overweight people, there's a sort of permission-giving going on. We're encouraging each other to eat more."
Wanting to be proactive about losing weight doesn't mean dropping overweight friends because making the decision to eat healthier can just as easily influence those around you to do the same.