1 in 5 children in the U.S. enter school overweight or obese, researchers find

About 17 percent of children in the United States are obese, according to federal health statistics. That’s a sobering statistic for parents to ponder as September marks National Childhood Obesity Month.

“One in five children in the U.S. enter school overweight or obese. Many kindergarteners with normal weight end up gaining too much weight during elementary school,” said Ashlesha Datar, a senior economist and director of the Program for Children and Families at USC Dornsife.

Excess weight during early childhood isn’t just a passing phase that disappears when a child starts hitting growth spurts, either, Datar said. Children who are overweight have a substantially higher risk of obesity as teenagers and adults, too.

“Because obesity is linked with serious health consequences, addressing excess weight gain in early childhood should be a top priority,” she said.

The emphasis of most early childhood programs is on cognitive and social and emotional readiness, Datar noted.

“Childhood obesity may decrease if entering school ‘ready to learn’ included the formation of good habits that promote healthy body weight,” she said. “Reinforcing healthy behaviors in early childhood can create wholesome habits as children transition through adolescence and adulthood.”

Americans devour sugar

Americans consume on average 22 teaspoons of sugar sweeteners every day — more than twice the recommended limits set by the American Heart Association and the World Health Organization.

Research has shown a clear link between devouring excessive amounts of sugar and obesity, Type 2 diabetes and heart disease. The abundance of high-sugar foods and the cues that go with them — the sight or smell of chocolate chip cookies, for example — can stimulate the brain pathways that control reward, attention and motivation and push us to eat more than we need,  said Kathleen Page, assistant professor of medicine at Keck School of Medicine of USC.

“Studies in animals suggest that diets high in sugar affect these brain pathways and can induce sugar craving-like behaviors,” she said. Understanding how this happens in people is critical to finding ways to reduce rising rates of diseases linked to unhealthful eating.

Scott Kanoski photo by Peter Zhaoyu Zhou.

Memory and cognition

Scott Kanoski, assistant professor of human and evolutionary biology and neurobiology at USC Dornsife, said research is showing that children who eat poorly may be have a harder time with memory and thinking later in life.

“Emerging findings reveal that excessive consumption of sugar and high-fat foods during childhood can have detrimental effects on memory and cognition,” he said.

For example, he explained, the hippocampus, a brain region that helps people remember life events and navigation routes, appears to be particularly vulnerable to childhood consumption of unhealthy food and drink.

Obesity does not exist on an island

Obesity is not an individual problem, according to Kayla de la Haye, assistant professor of preventive medicine at Keck School of Medicine.

The people around us “influence what we eat, if we are active and, ultimately, how we manage our weight,” she said. “We have to tackle obesity prevention collectively in families, peer groups and organizations. We have to create social networks that support healthy eating, activity and weight.”