Obesity prevalence increases among adolescents decreases or levels in younger children
Recent research in JAMA showed that during the last 3 decades the prevalence of obesity increased among adolescents, while recent trends indicated a decrease among children aged 2 to 5 years and a plateau for children aged 6 to 11 years.
“Obesity and extreme obesity in children and adolescents are associated with elevated blood pressure and abnormal fasting glucose and, long-term, often tracks into adulthood,” Cynthia L. Ogden, PhD, of the CDC’s National Center for Health Statistics, and colleagues wrote. “The purpose of this study was to investigate age-specific trends in the prevalence of obesity and extreme obesity in children and adolescents.”
The researchers analyzed data from 40,780 children aged 2 to 19 years participating in the National Health and Nutrition Examination Survey between 1988-1994 and 2013-2014. Participants were defined as obese if their BMI was at or above the 95th percentile on the CDC’s BMI-for-age growth chart. The researchers further defined participants as having extreme obesity if their BMI was at or above 120% of the 95th percentile.
Study data indicated that between 2011 and 2014, the overall prevalence of obesity among children aged 2 to 19 years was 17%; the overall prevalence of extreme obesity was 5.8%.
For children aged 2 to 5 years, the researchers found that between 1988 and 2004, obesity prevalence increased from 7.2% to 13.9% (P < .001) before dipping to 9.4% by 2014 (P =.03). Similarly, obesity prevalence among children aged 6 to 11 years grew from 11.3% during the 1988-1994 survey to 19.6% in 2008 (P < .001), and then leveled off at 17.4% for 2013-2014.
Among adolescents aged 12 to 19 years, the prevalence of obesity grew from 10.5% to 20.6% during the period from 1988 to 2014 (P < .001). The researchers also wrote that extreme obesity among this age range increased from 2.6% to 9.1% during the same study period (P < .001).
Ogden and colleagues stated that BMI and the CDC’s BMI-for-age growth chart are not a perfect empirical measurement for determining health risks and cautioned that their study data be considered with this in mind.
“Body mass index is an imperfect measure of body fat and health risk,” the investigators wrote. “Children and adolescents are compared with a group of U.S. children in the 1960s to early 1990s, so the prevalence of obesity is dependent on the characteristics of the age-specific population during that period. In addition, among young children, small changes in weight can lead to relatively large changes in BMI percentile.”
In a related editorial, Jody W. Zylke, MD, deputy editor of JAMA, and Howard Bauchner, MD, editor-in-chief of JAMA, wrote that Ogden and colleagues’ findings confirm that the obesity epidemic in the U.S. continues to grow at an unrelenting pace, highlighting a need for innovative interventions.
“The obesity epidemic in the United States is now 3 decades old, and huge investments have been made in research, clinical care and development of various programs to counteract obesity,” Zylke and Bauchner wrote. “However, few data suggest the epidemic is diminishing. Perhaps it is time for an entirely different approach, one that emphasizes collaboration with the food and restaurant industries that are in part responsible for putting food on dinner tables.” – by David Costill
Disclosure: The researchers report no relevant financial disclosures.