The negative effects of childhood overweight and obesity on quality of life (QOL) have been shown in clinical samples, but not yet in population-based community samples. Health-related QOL, as defined by the World Health Organization, includes an individual's physical, mental, and social well-being.
Joanne Williams, Ph.D., of the Royal Children's Hospital and Murdoch Children's Research Institute, Melbourne, Australia, and colleagues, examined the hypothesis that QOL scores would decrease with increasing weight. The research included data collected in 2000 from the Health of Young Victorians Study, which was commenced in 1997. Individuals were recruited via a random 2-stage sampling design from primary schools in Victoria, Australia. Of the 1,943 children in the original group, 1,569 (80.8 percent) were resurveyed 3 years later at an average age of 10.4 years.
The researchers measured health-related QOL using the PedsQL 4.0, a short survey which assesses physical, emotional, social, and school functioning in a child. The survey was completed by a parent and by child self-report. Summary scores for children's total, physical, and psychosocial health and subscale scores for emotional, social, and school functioning were compared by weight category based on International Obesity Task Force cut points.
Of 1,456 participants, 1,099 (75.5 percent) children were classified as not overweight; 294 (20.2 percent) overweight; and 63 (4.3 percent) obese. The researchers found that the parent and child self-reported PedsQL scores decreased with increasing child weight. At the subscale level, child and parent reported scores were similar, showing decreases in physical and social functioning for obese children compared with children who were not overweight. Decreases in emotional and school functioning scores by weight category were not significant.
"Our results indicate that health-related QOL, or functioning, begins to decline as soon as a child is above average weight, with a gradual steepening as Body Mass Index (BMI) increases," the authors write. "The decrease was small for overweight children but more marked for those who were obese. These new observations are less dramatic than the much lower scores reported for children attending tertiary clinics, but are consistent with those observed for adults."
"These findings have both positive and negative implications. As for any chronic condition, a relatively small effect of overweight on children's functioning across multiple domains is welcome. However, if neither children nor parents perceive a health effect, it seems unlikely that they will seek health care or initiate behavioral change that might lead to a healthier BMI, and consequently lessen the long-term health risk for the current generation of children. Our findings may explain why so few parents of overweight children express concern about their child's weight, yet with a quarter of all children now overweight or obese, even a minor reduction in health-related QOL at an individual level is still likely to have a major effect at a population level," the authors conclude.
(JAMA. 2005; 293:70-76. Available post-embargo at www.jama.com)
Editor's Note: This study was supported by grants from the National Heart Foundation, Financial Markets for Children, and Murdoch Childrens Research Institute. Co-author Dr. Wake is supported by a National Health and Medical Research Council (NHMRC) Career Development Award; co-author Ms. Hesketh by an NHMRC Public Health Postgraduate Scholarship; co-author Dr. Maher by an NHMRC project grant to develop a measure of quality of life for children with cerebral palsy; and co-author Dr. Waters by a Victorian Health Promotion Foundation Public Health Research Fellowship.