Childhood obesity is caused and fed by a complex combination of factors, and researchers from the University of Exeter traced over 25 years of data to search for answers. As children age, risk factors transform the ways they gain weight and split the cause for America’s obesity epidemic. Their findings, published in the International Journal of Obesity, revealed two different “distinct” reasons for weight gain in toddlers compared to adolescents.

“Childhood obesity is one of the greatest health issues of our time,” the study’s lead author Terence Wilkin, a professor at the University’s Medical School, said in a press release. “If we are to develop strategies to intervene effectively, we must first understand the cause. This study indicates for the first time that childhood obesity has different causes, depending on the age of the child. We now need further studies to explore this in more depth, as it could have significant implications for health care.”

After observing a group of 307 children for over a generation, researchers found by the time a child reached five years, up to five percent of girls and four percent of boys were obese. By the time they reached their 16th birthday, up to 16 percent of girls, and 11 percent of boys were obese — but the reason for weight gain was different in each age group.

When children are toddlers, the rise in obesity over the years can be attributed exclusively to minorities and those with obese parents. But when they enter into the teenage stage, neither their race nor their parents play a forceful role in whether or not they become obese — instead it was their peers who influenced the unhealthy weight gain. With each age phase, parents and teachers need to approach prevention and treatment with individualized care. There cannot be a broad stroke one-size-fits-all solution for childhood obesity when the root causes change depending on the child's age bracket, according to researchers.

Over the last 30 years, childhood obesity has more than doubled in children and tripled among adolescents, according to the Centers for Disease Control and Prevention, and more than 70 percent of those children had at least one risk factor for heart disease. Poor diet and a sedentary lifestyle is a recipe for dangerous weight gain and life-long health consequences.

A recent nationwide survey found the high rates of physical inactivity have been steadily rising since 2009 and continue to threaten the childhood population. When children are conditioned to sit on the couch, it’s likely they will grow up to become another one of the couch potatoes of our country. According to a study conducted by Cornell food scientist Brian Wansink and his team, childhood eating habits will likely follow us for decades.

“If a child becomes conditioned to eat their favorite foods first, they might develop the long-term eating habit of filling up on the high-calorie goodies at the expense of the healthier salads, fruits, and vegetables,” Wansink writes in his book Mindless Eating. “That is a recipe for obesity.”

Source: Mostazir M, Jeffery A, Voss L, and Wilkin T. Childhood obesity: evidence for distinct early and late environmental determinants: A 12-year longitudinal cohort study. International Journal of Obesity. 2015.