Two years after CDC heralded a drop in obesity rates among the youngest children, authors of a new study say it's too soon to declare victory.
In February 2014, the CDC heralded news that the obesity rate among the nation’s youngest children, those aged 2 to 5, had fallen 43% over the past decade. With a story in The New York Times, and an article in JAMA, public health leaders proclaimed that perhaps, at long last, America’s war against childhood obesity was starting to work.
Not so fast, say authors of a new study in the journal Obesity, which analyzes data from 1999 to 2014 and reaches this grim conclusion: “There is no evidence of a decline in obesity prevalence in any group, despite substantial clinical and policy efforts targeting the issue.”1
Authors Asheley Cockrell Skinner, PhD, of the Duke Department of Medicine; Eliana M. Perrin, MD, MPH, of the University of North Carolina School of Medicine; and Joseph A. Skelton, MD, of Wake Forest School of Medicine; write that it’s not certain that obesity rates are rising or falling—it’s simply too soon to tell. What’s clear, they say, it that it’s too soon to declare victory.
The researchers examined data from the National Health and Nutrition Examination Survey (NHANES) for children age 2 to 19 years. The NHANES data are released every 2 years and are the same set CDC used in 2014 to conclude that the tide was turning.
However, in a series of tables covering the years 1999 through 2014, Skinner, et al, show the steady climb in the percentage of children and teens, both boys and girls, who are classified as overweight and in tiers of obesity of increasing severity.
In 1999, 28.8% of children were overweight and 14.6% were obese. By 2014, those percentages had increased to 33.4% being overweight and 17.4% being obese. CDC defines being overweight has having a body mass index (BMI) of greater than 25 but less than 30. At a BMI of 30, one is obese. A BMI of 35 is Class 2 obesity, and a BMI of 40 or higher is Class 3 obesity.
The news from 2 years ago was not incorrect, the data show. Rates for overweight and the first class of obesity, for both boys and girls—did drop between 2010 and 2012. The trouble is, the rates went right back up by 2014. The authors compare obesity rates to what happened with smoking rates as they slowly fell over a 50-year period; in many years, there were intervals without declines.
“Only with ongoing data will we be able to recognize whether the apparent leveling off of obesity represent real change or whether prevalence will continue to rise,” they write.
The authors are particularly concerned with rising rates of severe obesity among children. In 1999, less than 1% of children had Class 3 obesity; by 2014, 2.4% had this classification, and it had jumped from 1.7% just since 2010. “These higher obesity levels are associated with increased cardiometabolic risk, and there is little evidence that severe obesity can be addressed through population-level policies alone,” the authors write.
Data also reveal significant and growing racial disparities in obesity; it is less prevalent among whites than among Hispanics and blacks. Obesity rates among Hispanic boys were 41.3% for 2013-2014; and rates for black girls were 41% for that period. Over the past decade, black girls have been at the highest risk for severe obesity, but that dipped in 2013-2014.
Obese children tend to become obese adults, at risk of significant health issues and early death unless they are able to gain access to bariatric surgery, which is expensive and has certain risks, the authors note.
An accompanying editorial2 does not entirely support the authors’ findings that no progress is being made, based on documented success in some states and individual communities, as well as declining sales of sugary drinks, fast food, and pizza. However, as documented by the Center for Science in the Public Interest, these changes are not uniform across the United States—Southeastern states, in particular, have less healthy diets and drink more soda.
“The 4.5 million children and adolescents with severe obesity will require novel and intensive efforts for long-term obesity improvement. With scarce resources, and increasing costs of comorbid conditions, there is an urgent need for targeted interventions to stem the rise in obesity among children, in addition to policies and clinical efforts designed to prevent obesity,” the authors conclude.
1. Skinner AC, Perrin EM, Skelton JA. Prevalence of obesity and severe obesity in US children, 1999-2014 [published online April 26, 2016]. Obesity. 2016; doi:10.1002/oby.21497.
2. Dietz WH. Are we making progress in the prevention and control of childhood obesity? It all depends on how you look at it [published online April 25, 2016.] Obesity. 2016; DOI: 10.1002/oby.21518.