Chronic Obesity Linked to Behavior Problems in Kids 

Monday April 7, 2003

By Charnicia E. Huggins

NEW YORK (Reuters Health) - Children who are chronically obese may be more likely to develop certain mental health problems than their peers, according to a new report released Monday.

The eight-year study of nearly 1,000 white youth found that girls and boys who were obese at each annual follow-up were more likely than their non-obese peers to have symptoms of oppositional defiant disorder, meaning they tended to defy rules. Chronically obese boys, but not girls, were also much more likely to have symptoms of a depressive disorder.

The same was not true, however, of boys and girls whose weight fluctuated throughout the study period, those who were obese during late childhood or those who became obese during adolescence, the report indicates.

"The key implication of the findings is that obesity, which is linked to increased risk for so many health problems, is also linked to increased risk of psychiatric disorder in children and adolescents," study author Dr. Sarah A. Mustillo of Duke University Medical Center in Durham, North Carolina, told Reuters Health.

Studies have shown obesity to be associated with many health problems, including lung, gastrointestinal and circulatory problems during childhood and increased risk of cardiovascular disease, diabetes and colon cancer in adulthood. Overweight and obese adults are also known to be more likely to develop psychological disorders than normal-weight adults, but more research is needed to determine if the same is true for children.

To investigate, Mustillo and her colleagues studied 991 North Carolina youth, aged 9 to 16, who were involved in a long-term mental health study.

Although weight fluctuated during the pre-teen and teenage years, the prevalence of obesity generally increased with age, the researchers note. By age 16, about one in five teens were obese.

Overall, 73 percent of the youth were never or rarely obese, five percent were obese only during late childhood and 7.5 percent became obese during adolescence. Fifteen percent were chronically obese -- a rate three times higher than the authors predicted using the most recent criteria from the Centers for Disease Control and Prevention (news - web sites), they note in the journal Pediatrics.

Chronically obese children were more than twice as likely to have symptoms of oppositional disorder than non-obese boys and girls, study findings indicate. And chronically obese boys, but not girls, were nearly four times as likely to have symptoms of depression.

All of the study participants were raised in families with similar parenting styles and family structure. There were no differences in their family's history of mental illness and they had similar exposure to drug abuse, crime and traumatic events, the report indicates.

Why obesity was associated with an increased risk of psychiatric disorder is unknown. Since the psychiatric symptoms were most common in the chronically obese group, it may be that the children's obesity increased their risk of depression or behavior problems, the researchers speculate.

"Obesity may lead to poor treatment and discrimination from peers, which could then in turn increase the risk of behavior problems," Mustillo said. "Or, obesity could lead to isolation from peers or withdrawal from activities, which could increase the risk for depression."

On the other hand, it could be the children's psychiatric disorder that increases their risk of obesity, the researchers add.

Parents can help reduce their child's risk by first reducing their child's risk of becoming obese, according to Mustillo. "We live in a country with super-sized meals and sedentary lifestyles," she said. "Parents can encourage, model and support nutritious eating and higher levels of physical activity."

And for parents whose children are already obese, they should "emphasize the health aspects as opposed to the appearance aspects of losing weight, to avoid emphasizing physical appearance," Mustillo said. If any emotional or behavioral problems are suspected, she added, parents should consult a health care professional.

SOURCE: Pediatrics 2003;111:851-859.

HOME