(RxWiki News) Parents and policymakers worried about the junk food offerings at schools may be focusing their anger in the wrong direction, according to a new study.
To the surprise of even the sociologists who conducted the research, whether a school makes high-calorie and high-fat snacks available to students plays no part in obesity rates at those schools.
"Keep your home stocked with healthy snacks."
Lead author Jennifer Van Hook, a sociology professor at Penn State, said the results were so surprising that the researchers spent an extra two years reviewing their data to ensure they had not missed something.
“There has been a great deal of focus in the media on how schools make a lot of money from the sale of junk food to students, and on how schools have the ability to help reduce childhood obesity,” Van Hook said.
“In that light, we expected to find a definitive connection between the sale of junk food in middle schools and weight gain among children between fifth and eighth grades," she said.
In fact, they found the opposite - a slight decrease in obesity over those three years.
Van Hook and her colleague Claire Altman used data from a group of 19,450 children included in the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999.
This longitudinal study tracked a nationally representative group of students across the U.S. for eight years - from kindergarten to eighth grade - but Hook's sample came from students who attended schools in the same county in both fifth and eighth grades.
Within that county, 59 percent of fifth graders and 86 percent of eighth graders went to schools that sold candy, soda, chips and similar junk foods.
Despite this increase in children attending schools with junk food offerings, obesity among the students dropped from 39 percent to 35 percent between fifth and eighth grades.
Childhood obesity has become a more prominent issue in the past several years, especially as First Lady Michelle Obama has made tackling it one of her most important and most publicized initiatives.
The concern is well-founded: the percentage of obese children has tripled in the U.S. over the past four decades.
Further, the health risks of being severely overweight are well known: hypertension, increased risk for heart disease and cardiovascular problems, increased risk for diabetes, and a host of other health problems.
Yet, Van Hook said her research shows that simply targeting schools' meals and snacks is misguided.
"Our study suggests that—when it comes to weight issues—we need to be looking far beyond schools and, more specifically, junk food sales in schools, to make a difference,” she said.
Van Hook points out that home and extracurricular environments need to be considered as well in the efforts to fight childhood obesity.
She added that one reason schools' high-fat or high-calorie snacks might not play a big part in obesity rates is that students only have specific fixed times when they are typically able to eat in middle school.
"As a result, whether or not junk food is available to them at school may not have much bearing on how much junk food they eat,” Van Hook said.
Eve Pearson, a registered and licensed dietitian, agrees that home is more likely where kids are ingesting their extra unhealthy calories.
"There's not a lot of time for students to eat and/or drink at school because they're preoccupied with friends," Pearson said. "When they get home from school, they hit the pantry and never stop eating."
She adds that many of these kids are eating a "yellow" diet: french fries, fish sticks, chicken tenders and corn.
"They get very little color in their diets," said Pearson, whose clientele has included a lot of kids. "There's definitely more to work on that just the offerings at school."
Van Hook suggests, turning attention to helping younger students develop healthy eating habits early on may be more fruitful.
“There has been a lot of research showing that many children develop eating habits and tastes for certain types of foods when they are of preschool age, and that those habits and tastes may stay with them for their whole lives,” Van Hook said.
The study appears in the January issue of Sociology of Education. It was funded partly by a grant from the Foundation for Child Development. The authors did not disclose any conflicts of interest.