Dear EarthTalk: I hear that many school cafeterias have nutrition standards no better—even worse—than those of fast food chains. What can be done about this? — Betsy Edison, Nashville, TN

Americans have done a great job making sure that our kids have something to eat at school regardless of socioeconomic status, with the National School Lunch Program providing low-cost or free lunches to upwards of 31 million students at 92 percent of U.S. public and private schools.

But that doesn’t mean the food has been especially nutritious, and public health experts say it’s no wonder our kids are more obese than ever when we feed them trans fats, salts and sodas for lunch. Kids get half their daily calories at school, so what’s for lunch there has a big impact on health and lasting eating habits.

A 2008 analysis of school lunches by the Institute of Medicine (IOM) concluded …