The prevalence of childhood obesity among all Philadelphia students dropped more than 4.5 percent between the 2006-07 and the 2009-10 school years, according to a study published online today in the journal Preventing Chronic Disease.
Childhood obesity continues to be a problem in the U.S. despite numerous federal and statewide efforts over the past decade to intervene. An analysis published earlier this year in the Journal of the American Medical Association found that while the overall rate of childhood obesity in the U.S. remained relatively steady over the past decade, more young males are considered obese now than in 2000.
In Philadelphia, on the other hand, childhood obesity appears to be on the decline across age, gender, and racial lines. The study authors analyzed height and weight data from more than 100,000 students, ages 5 to 18, in the Philadelphia school district, calculating the prevalence of obesity overall and among student subgroups based on body mass index (BMI).
For the sake of the study, students were defined as "obese" if their BMIs were equal or exceeded the 95th percentile of the age-based average, as defined by the U.S. Centers for Disease Control and Prevention. "Severe obesity," on the other hand, only applied to students with a BMI greater than or equal to 35, or greater than or equal to 120 percent of the age-based obesity threshold.
From the 2006-07 to 2009-10 school years, the prevalence of obesity dropped from 21.5 percent to 20.5 percent, according to the study, with the largest decrease occurring between the 2006-07 and 2008-09 school years. Males were, on average, slightly more likely to be obese at the start of the study, but by the end of the four years, females had overtaken males in terms of obesity rate.
Similarly, the rate of severe obesity declined over that four-year span, going from 8.5 percent in the 2006-07 school year to 7.9 percent in 2009-10. To put it another way, severe obesity still affects roughly one in 12 Philadelphia schoolchildren.
The severe-obesity rate exceeded 9 percent with Hispanic males and African-American females, while African-American males and Hispanic females were the groups that experienced the largest statistical changes in obesity and severe-obesity rates. Asian females finished with the lowest rates of obesity and severe obesity, by far.
"These data suggest that the epidemic of childhood obesity may have begun to recede in Philadelphia," the authors concluded, "but unacceptably high rates of obesity and severe obesity continue to threaten the health and futures of many school children."
What's behind the decline? The study authors can't say for certain, but point to a few new initiatives and policies, including the removal of soda and sugar-sweetened beverages from school vending machines and the decision to stop using fryers in school cafeterias.
Not Just Philadelphia
Earlier this year, a similar trend was noted in New York City, where the obesity rate of K-8 public students decreased 5.5 percent since the 2006-07 school year.
A study published online in April in the journal Pediatrics also found the childhood-obesity rate in Massachusetts to have "substantially decreased" among both boys and girls younger than 6 in the mid-2000's.
A new brief from the Robert Wood Johnson Foundation (RWJF) details the progress that certain cities and states have been making in terms of reducing the rate of childhood obesity. Beyond Philadelphia and New York City, Mississippi and California have both reported declining childhood obesity rates over the past half-decade.
In a commentary accompanying the new Philadelphia study, RWJF president and CEO Risa Lavizzo-Mourey and Jim Marks, the Senior V.P and Director of RWJF's Health Group, write that Philadelphia is "crucial proof of the concept that communities can reduce obesity rates—and do so in a way that helps to close the disparities gap." Lavizzo-Morey and Marks encourage readers to learn from Philadelphia's success and emulate effective policies.
"Good health is crucial to the pursuit of happiness called for in the Declaration of Independence," they write. "For our nation's young people to have equal opportunity to pursue happiness, they also must have equal opportunity for good health, regardless of where they live."
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