After rising steadily for more than 10 years, the proportion of U.S. kids defined as obese due to a large waist circumference held steady between 2003 and 2012, according to a new analysis of national data.
The new results echo recent studies that found the increase in U.S. obesity rates has slowed over the past several years (see Reuters story of August 16, 2013 here: reut.rs/1iWcaVi).
“Even though the trends were flat across the years, the prevalence of abdominal obesity is still too high,” said senior author Lyn M. Steffen, from the School of Public Health at the University of Minnesota in Minneapolis.
Abdominal obesity refers specifically to “visceral fat,” or the fat that accumulates around the midsection. This can be measured by waist circumference or by a waist-to-height ratio.
Using biennial data from a nationwide health and nutrition study, Steffen and her coauthors found that about 18 percent of kids ages two to 18 were obese based on their waist circumference in 2011 and 2012, very close to the rate in 2003 and 2004.
Kids who qualify for abdominal obesity have a waist circumference larger than a given cutoff determined by their age and gender.
In the same group, 33 percent of kids ages six to 18 were considered obese based on their waist-to-height ratio, according to results published in Pediatrics. That means their waist circumference equaled at least half of their height.
The findings are based on assessments of almost 17,000 children.
The only change in abdominal obesity between 2003 and 2012 came among kids ages two to five, whose abdominal obesity rates decreased by between three and five percent.
Kids who are obese or overweight often remain in that category as adults, Steffen said.
Fat around the midsection is a good indicator of increased risk for metabolic syndrome, high blood pressure, heart disease and diabetes, she said, and abdominal obesity is a greater risk than general obesity.
This study did not address why obesity trends may be leveling off in the U.S., but it could be due to policy changes highlighting the dangers of sugar-sweetened beverages, Steffen suggested.
“Number one, it’s good, the prevalence of abdominal obesity remained the same over the last eight years, that’s good, but the prevalence is still high, so we need to think about what to do to lower the numbers,” she told Reuters Health.
Asheley Cockrell Skinner agreed there are still concerns.
“Recent publications tell us that overweight and obesity in general are leveling off, but the more severe forms of obesity are increasing,” Skinner told Reuters Health by email.
She studies health policy, management and pediatrics at the UNC Gillings School of Global Public Health in Chapel Hill, North Carolina and wasn’t involved in the new research.
More severe levels of abdominal obesity could still be increasing, but this study only looked at one large category of obesity, Skinner said.
“I don’t think this tells parents very much on its own,” she said. “However, it does raise the important issue of abdominal obesity.”
An “apple-shaped” body has more abdominal obesity than a “pear-shaped” body, she noted.
“Parents should be aware that abdominal obesity is a greater risk, and may help doctors identify which children are at greatest risk for health problems,” Skinner said.