In addition to the usual contributors to child obesity — excessive TV watching and indulging in sugary sodas, for instance — a new study finds another major culprit: eating school lunches.
Researchers studied 1,003 sixth-graders, 150 of whom were clinically obese, at a Michigan middle school, and recorded their overall eating habits, extracurricular activities and school lunch consumption. (More on Time.com: New Dietary Guidelines: Cut Salt and Sugar, Eat More Fish)
On many measures of unhealthy eating, the obese and normal-weighted students didn’t differ much. While 7.7% of obese children reported eating fatty meals like hamburgers, ribs, steak and hot dogs in the previous 24 hours, even more non-obese kids — 11.2% — reported doing the same. And slightly fewer obese children than non-obese children reported eating French fries or chips the previous day.
But the numbers diverged when it came to school lunch: the researchers found that kids who ate school lunches were 29% more likely to be obese than kids who brought lunch from home. Soda consumption was also predictive of obesity: compared with 39.7% of obese kids who reported drinking soda in the previous 24 hours, 30.4% of non-obese kids did the same.
Obese kids were also more sedentary than their thinner peer. Kids who watched TV or played video games for two or more hours a day — indicating a sedentary lifestyle — were 19% more likely to be obese than kids who logged less screen time. Obese kids were less likely to participate in school-run exercise programs like gym class and team sports. (More on Time.com: Elmo at the White House? Monster Plugs School Lunch Bill)
Researchers also recorded the children’s blood pressure, cholesterol and blood glucose levels and heart rate following a stress test. Predictably, obese children scored significantly worse on all measures than thin kids.
But just because 85% of the study participants weren’t obese that didn’t mean they had stellar lifestyle habits. Only one-third of the study’s participants reported getting half an hour of daily exercise at least five days each week. One-third of students said they’d had a soda in the previous day, and fewer than half said they had eaten at least two servings of fresh fruits and vegetables. The latest government guidelines recommend that half of each meal consist of fresh produce.
On that last point, schools are getting help. The Obama administration’s new Healthy, Hunger-Free Kids Act of 2010, signed into law last December, sets aside $4.5 billion over 10 years to fund school lunches and child nutrition programs; it requires school lunch programs to double the amount of fresh fruits and vegetables in each meal, reduce calories and expand access to drinking water during meal time. With 31 million children receiving school lunches and 20% of all U.S. children suffering from obesity, the measure should help to improve the food environment, at least for one meal a day.