Obese and overweight family and friends inadvertently influencing those around them to become obese or overweight has contributed to a national epidemic, according to new research at Colorado State University, Regis University and the University of Colorado Health Sciences Center.
People’s social circles hold great influence over whether or not they are or will become overweight, but researchers think those circles also can influence the U.S. population back to a healthier weight. By combining the targeting of a small number of people to reduce or maintain their weight at a healthy level with societal incentives or disincentives, rates of obesity would decrease.
Close relationships play such a key role in the growing trend in the United States toward obesity that even people who successfully lose weight are likely to slip back into being overweight if their friends and family are overweight. Using a computer model, the researchers have demonstrated how normal and even underweight individuals who are surrounded by obese or overweight individuals also will eventually become overweight.
But when members of a social cluster are able to maintain or reduce their weight to a normal level, this influences their friends to be healthy, and the trend reverses. Along with targeting two other key factors – societal forces that lead to frequent and easy indulgence in high-calorie food and the nation’s sedentary lifestyle – researchers hope their models will help slow the nation’s alarming skate toward an obese majority. David Bahr, physics and computational science professor at Regis University in Denver, developed the computer model simulations of social structures for the study.
"Our research shows that the United States has already reached or passed a tipping point, and without effective interventions, will continue its rapid slide toward a nation with almost all of the population struggling with obesity," said Raymond Browning, professor in Colorado State University’s Department of Health and Exercise Sciences and one of the researchers on the project. "With a few exceptions, our research model shows that if you are more likely to go have a beer and pizza with your friends than you are to go for a bike ride or hike, you’ll eventually become overweight. How you spend your social time with friends and family – and their influence on your behaviors – has a tremendous impact on your weight and activity level. That’s why most weight loss interventions don’t work.
"If we use the power of those social network connections in a different way, we can influence people to maintain a healthy weight or lose excess pounds," Browning added. "By ‘pinning’ down the weight and activity level of key people within a social network to maintain a healthy weight, those individuals influence their friends to be healthy and active, and we may be able to slow the nation’s progression toward obesity."
Community intervention programs to target even 1 percent of a community’s individuals, including normal-weight individuals based on body mass index measurements, would be enough, when combined with social forces that encourage healthy behaviors. Social forces would include measures such as tax breaks for losing weight. These strategies could decrease the number of overweight individuals by creating a critical mass that converts most or all of the population to a healthier weight.
"Our computer simulations show that changing the body mass index of an individual at the center of a social cluster is very difficult because surrounding neighbors will pull the individual back to their original weight," Browning said. "Because of this cluster inertia, our simulations demonstrate why interventions targeted toward obese people without regard to their social networks fail."
Browning said that people who successfully lose weight often gain it all back and then some because their eating and activity habits are influenced by others around them. Although weight intervention programs cannot uproot social networks, having a healthy, normal weight person work to influence the health of people within their social cluster is key. Such influences would be as simple as suggesting active social gatherings instead of high-calorie food-based socializing.
However, healthy friends can’t do it alone; the authors propose changing societal influences and embarking on a social campaign much like that successfully used to reduce the number of people who smoke, decreasing the availability or desirability of unhealthy, high-calorie fast food, and building environments that encourage physical activity. For example, businesses and communities should be more conscientious of how they can build activity into a community, such as encouraging biking and walking over parking close to a destination. In the fight against an increasingly overweight and unhealthy society, Browning points out that active lifestyles are key.
"You can be lean and inactive and you are at greater risk of death from a chronic disease than you if you are active and overweight," Browning said. "I would like to see America focus on our levels of physical activity rather than our weight."
Applying social forces such as tax incentives for healthy weights, advertising that promotes active lifestyles, "carrots and sticks" measures to reward healthy weights such as businesses that offer employee bonuses for weight loss or maintaining a healthy weight, and penalizing behavior that leads to being overweight or obese would provide motivation for people to change. Coupled with targeting specific, well-connected individuals of a social network with effective weight management strategies, the influence of these "social celebrities" may stabilize or reverse trends in weight gain in the larger society.