The New York Times “Vital Signs” column reports today on a study of more than a thousand Michigan sixth graders which found that those students who regularly ate school lunch were 29% more likely to be obese than those who brought lunch from home.
This finding bolsters my own conclusions on this subject.
You might recall that back in September I wrote a post called “Can a Child Become Overweight Just from Eating School Lunch? — A TLT Experiment” I invented an eight-year old boy, Jimmy, and gave him an average height and weight using CDC growth charts. I then calculated Jimmy’s caloric needs for the day and generously alloted 1/3 of his calories toward lunch — generous because this assumed that, unlike almost all children, he wasn’t eating snacks between meals. I then sent Jimmy through my Houston district’s elementary school lunch line over the course of a single week, letting him pick and choose from the week’s menu as he wished (lots of chocolate milk, tacos, burgers and the rest).
My conclusion? On a daily basis, Jimmy exceeded his artificially high calorie maximum at lunch by an average of 231.8 calories. And since a pound of weight gain represents 3,500 unneeded calories, an extra 350 calories of food a day would cause a child to gain an extra pound every ten days (350×10).
The good news, as noted in the Times article, is that under the new USDA school food regulations, calorie minimums for school meals are going down, and a broader variety of fruits and vegetables (not just corn and potatoes) will be offered.
It remains to be seen how little Jimmy will fare on the new school food. I’ll revisit this experiment using my school district’s revised menus when they’re in effect.
[Hat tip: June Edelstein]
Diane Pratt-Heavner says
Take a closer look at the study.
The researchers also found that obese students were much more likely to have consumed regular soda or soft drinks. The report goes on to say that “there was a consistent trend for obese students to report less healthy lifestyle activities. Significantly fewer obese students exercised regularly, participated in physical education classes, or were a member of ≥1 school sports teams or out-of-school sports teams. Obese students also reported more TV watching, computer game use, and video game use (Table IV). Perhaps most notable was that 58.2% of obese students reported having watched ≥2 hours of TV in the prior 24-hour period.”
The study did not inquire about socio-economic status. Research has linked low socio-economic status with overweight and obesity, and children from low-income families are far more likely to participate in school meals, due to the free and reduced price program.
bettina elias siegel says
Diane: I did wonder if the researchers controlled for socioeconomic status, since children are more likely to eat school lunch when their parents can’t afford anything else, and those economically disadvantage home environments may also contribute to obesity. Do you have a link to the actual study? Thanks, and thanks for stopping by. – Bettina
KL says
I was going to comment on the correlation/causality fallacy also, i.e., that the correlation between two data does not necessarily mean that one causes the other. It is also possible that there may be a third (or fourth, or fifth…) factor that influences both of them, or their causes may be unrelated.
It certainly may be possible that school food is making kids fat. It seems unlikely, though, that if it is a cause it would be the only one. I agree with the previous poster that kids who qualify for free and reduced lunches are going to eat more meals in the cafeteria than their classmates whose parents can afford to send a lunch. These lower-income families have been shown to be less likely to provide nutritious meals at home, or to eat together as a family, both of which are also correlated with obesity. And the other factors mentioned by the previous commenter might also have something to do with the study results as well.
It is important to look at data objectively and not make assumptions about causality without explicit evidence.
bettina elias siegel says
KL — I think I was the previous poster 🙂 and Diane of the School Nutrition Association just sent me the study off line. I’ll take a look and report back. Thanks for your comment! – Bettina
jenna Food w/ Kid Appeal says
I linked up to this in my post today, thanks for sharing. perfect timing for the pilot that begins Monday in one SBISD elementary campus
Renee says
It may well be true that there are factors at home that began the journey to obesity for the kids in this study, but it seems likely that the bad food given to them through school lunches would only make the problem worse. Just another reason to make sure school lunches are nutritious.
It also makes it more important that physical activity be emphasized at school, and by this I mean more recess/activity, not necessarily more sports –kids who are overweight and out of shape are likely to avoid sports, where competition is more important than health.