Is Weight Gain Contagious?
How did we get to that "flood stage" of obesity? Maybe you should look around you.
"Our work suggests that weight gain spreads in social networks," says Christakis, who has researched the spread of obesity.
His findings, published in The New England Journal of Medicine in 2009, show that your odds of becoming obese rise by 57% if you have a friend who becomes obese and by 40% if your sibling becomes obese."We're social animals," Christakis says. "We're influenced by the choices and actions and appearance and behaviors of those around us."
In short, our social contacts -- the people in our lives -- have a big influence on what we eat, how much we exercise, and how we judge our own appearance. This may help explain why obesity rates are not the same throughout the country. In fact, there are what might be called obesity hotspots.
Jana Gordon Bunsic, DO, has seen evidence of this first-hand in her practice. She's a board-certified family physician and clinical nutritionist in Morristown, Tenn. – a town in a state with one of America's highest obesity rates.
"Upon moving my family and my medical practice to east Tennessee, I was immediately surprised by the prevalence of obesity in the area," says Bunsic, who used to live in south Florida. She cites a culture that's fond of "biscuits and gravy," as well as too little exercise. "The society is quite rural, and few people walk or ride bikes from place to place."
With obesity being so common, Bunsic finds her patients have a skewed idea of what's normal. "A 16-year-old patient came in with his mother the other day," she recalls. "By following my recommendation, he had lost 45 pounds… His mother was very concerned he was starting to become too thin" even though he was still overweight by medical standards.
Skewed perceptions are not confined to Tennessee.
"It's taking more and more weight as time goes by for people to judge themselves heavy," Christakis says. In a study using government data, he found that obese people generally knew they were obese 20 years ago. That's not necessarily the case anymore. In 2007, a National Consumers League survey showed that although 34% of adult survey participants were obese, only 12% said they had ever been told that by a health care professional.
Contributing to these changing perceptions is a fashion trend known as vanity sizing. Manufacturers have made clothing sizes more forgiving over the years. "This is making women feel good about themselves," Kushner says, "but the bad thing is it's supporting the weight increase in the population."