Although kids can typically adjust their energy intake by regulating their food, Temple University public health professor Jennifer Fisher says, their surroundings and options may change that equation for kids in the same way that it does in adults. Image: Flickr/The Familylee
New evidence is confirming that the environment kids live in has a greater impact than factors such as genetics, insufficient physical activity or other elements in efforts to control child obesity. Three new studies, published in the April 8 Pediatrics, land on the import of the 'nurture' side of the equation and focus on specific circumstances in children's or teen's lives that potentially contribute to unhealthy bulk.
In three decades child and adolescent obesity has tripled in the U.S., and estimates from 2010 classify more than a third of children and teens as overweight or obese. Obesity puts these kids at higher risk for type 2 diabetes, cardiovascular disease, sleep apnea, and bone or joint problems. The variables responsible are thought to range from too little exercise to too many soft drinks. Now it seems that blaming Pepsi or too little PE might neglect the bigger picture.
"We are raising our children in a world that is vastly different than it was 40 or 50 years ago," says Yoni Freedhoff, an obesity doctor and assistant professor of medicine at the University of Ottawa. "Childhood obesity is a disease of the environment. It's a natural consequence of normal kids with normal genes being raised in unhealthy, abnormal environments." The environmental factors in these studies range from the seemingly minor, such as kids' plate sizes, to bigger challenges, such as school schedules that may keep teens from getting sufficient sleep. But they are part of an even longer list: the ubiquity of fast food, changes in technology, fewer home-cooked meals, more food advertising, an explosion of low-cost processed foods and increasing sugary drink serving sizes (pdf) as well as easy access to unhealthy snacks in vending machines, at sports games and in nearly every setting children inhabit—these are just a handful of environmental factors research has linked to increasing obesity, and researchers are starting to pick apart which among them play bigger or lesser roles in making kids supersized.
Size matters in "obesogenic environments"
In one of the three new studies dishware size made a big difference. Researchers studied 42 second-graders in which the children alternately used child-size 18.4-centimeter (7.25-inch) diameter plates with 237-milliliter (8-ounce) bowls or adult-size 26-centimeter (10.25-inch) diameter plates with 473-milliliter (16-ounce) bowls. Doubling the size of the dishware, the researchers found, increased the amount of food kids served themselves in a buffet-style lunch line by an average of 90 calories. They ate about 43 percent of those extra calories, on average.
Although kids can typically adjust their energy intake by regulating their food, Temple University public health professor Jennifer Fisher says, their surroundings and options may change that equation for kids in the same way that it does in adults. "This notion that children are immune to the environment is somewhat misguided," says Fisher, who headed up the study. "To promote self-regulation, you have to constrain the environment in a way that makes the healthy choice the easy choice."
Fisher says much recent research in nutrition has focused on the "obesogenic" environments of today's society: a dietary environment offering widespread access to highly palatable foods in large portion sizes. "If we look at adult studies on dieting and weight loss, we know that the prospect of maintaining self-control in this environment is fairly grim," Fisher says. "I think most scientists believe our bodies have evolved to pretty staunchly defend hunger and prevent weight loss, and maybe are not so sensitive in preventing overconsumption."