Monday, March 15, 2010

Kids Who Eat School Lunch Are Fatter

By Ed Bruske
aka The Slow Cook

Middle school children who regularly eat school lunches are more likely to be overweight or obese, develop poorer eating habits and have high levels of “bad” cholesterol compared to those who bring lunches from home, according to new study from the University of Michigan.

The study, which examined the eating habits of nearly 1,300 sixth-graders over a three-year period, found that those who at the lunch served at school ate more fat, drank more sugary beverages and consumed fewer fruits and vegetables.

The same students had higher levels of LDL (low-density lipoproteins), or "bad" cholesterol, compared to their peers who ate lunch prepared at home.

“This study confirms the current and escalating national concern with children’s health, and underscores the need to educate children about how to make healthy eating and lifestyle choices early on,” says Elizabeth Jackson, M.D., MPH, assistant professor of internal medicine at the U-M Health System. “Although this study doesn’t provide specific information on nutrient content of school lunches, it suggests there is a real opportunity to promote healthy behaviors and eating habits within the school environment. This is where kids spend a majority of their time.”


  1. There are a couple of problems with the study conclusions (which the authors acknowledge):

    1. The study is in Michigan, and MI could have completely different school lunches than those in other states. The program is very heterogeneous.

    2. Selection effects: For example, what if kids who are more likely to eat school lunch are also more likely to overeat and/or eat poor quality diets? Two colleagues that work on diet intake say that's generally true (i.e. low income/low educated have worse diets). The fact that the authors don't control for education or income makes it hard to conclude that the school lunch itself is to blame for their poor diets and poor choices at school (or home). The SNDA studies compare similar kids (with a rich dataset) and they find that all kids eat poorly, both at home and at school and that there are no statistical differences between NSLP participants and non-participants. The policy recommendations from that work are also that school lunches need to be improved, but mostly because it's an opportunity to influence kids, not necessarily that school lunches are a whole lot worse overall.

  2. Everything you say is exactly right, Constance. I'll have more on this tomorrow.