Much medical research has noted a significant risk of adult health problems in individuals that are obese as children; however, a new UCLA study has found that child obesity is linked to more immediate health problems to a much greater extent than previously thought. The study is currently available online and will be published in the January–February print edition of the journal Academic Pediatrics.
The researchers found that compared to children who are not overweight, obese children are at nearly twice the risk of having three or more reported medical, mental, or developmental conditions. In addition, overweight children are at 1.3 times higher risk. Lead study author Dr. Neal Halfon is a professor of pediatrics, public health and public policy at UCLA where he directs the Center for Healthier Children, Families and Communities. He explained, “This study paints a comprehensive picture of childhood obesity, and we were surprised to see just how many conditions were associated with childhood obesity. The findings should serve as a wake-up call to physicians, parents and teachers, who should be better informed of the risk for other health conditions associated with childhood obesity so that they can target interventions that can result in better health outcomes.”
The researchers note that with the sharp increase in childhood obesity over the past two decades, there has been a parallel rise in the prevalence of other childhood-onset health conditions, such as attention deficit–hyperactivity disorder, asthma, and learning disabilities. However, previous studies on the topic have been limited due to a narrow focus on a specific region of the nation, a small sample size or a single condition. Therefore, they designed a large population-based study of children in the United States to evaluate the impact of child obesity. They note that their study provides the first comprehensive national profile of associations between weight status and a broad set of associated health conditions, or co-morbidities, that children suffer from during childhood.
The researchers found that, overall, obese children were more likely than those who were classified as not overweight to have reported: poorer health; more disability; a greater tendency toward emotional and behavioral problems; higher rates of grade repetition, missed school days, and other school problems; ADHD; conduct disorder; depression; learning disabilities; developmental delays; bone, joint and muscle problems; asthma; allergies; headaches; and ear infections.
For the study, the researchers accessed data from the 2007 National Survey of Children’s Health; they analyzed data on almost 43,300 children between the ages 10 and 17. They assessed associations between weight status and 21 indicators of general health, psychosocial functioning, and specific health disorders. The data was adjusted for sociodemographic factors.
The investigators found that 15% of the children were considered overweight (a body mass index (BMI) between the 85th and 95th percentiles), and 16% were obese (a BMI in the 95th percentile or higher).
The investigators theorized that the ongoing shift in chronic childhood conditions is likely related to decades of underappreciated changes in the social and physical environments in which children live, learn, and play. They recommend that obesity-prevention efforts should target these social and environmental influences and that kids should be screened and managed for the co-morbid conditions.
The researchers cautioned that while the strength of the current study lies in its large population base, future studies are indicated to further evaluate longitudinal data (data over a time span) to determine causal relationships that cannot be inferred from a cross-sectional study. “Obesity might be causing the co-morbidity, or perhaps the co-morbidity is causing obesity—or both might be caused by some other unmeasured third factor,” noted Dr. Halfon. “For example, exposure to toxic stress might change the neuroregulatory processes that affect impulse control seen in ADHD, as well as leptin sensitivity, which can contribute to weight gain. An understanding of the association of obesity with other co-morbidities may provide important information about causal pathways to obesity and more effective ways to prevent it.”