Frustration spilled over last week in response to the U.S. Department of Agriculture's failed attempt to keep pizza from being counted as a vegetable in school lunch programs.

I say, let them eat pizza (in moderation). And let us, as the caring adults in kids' lives, get to work on much messier issues than what to call tomato paste.

The USDA argued that one-eighth of a cup of tomato paste, spread on pizza, should not count as a half-cup of vegetables. Congress rejected the USDA's attempt to tighten nutritional standards.

Obviously, the USDA is on to something. About 15 percent of children ages 6 to 18 are obese, which is defined as having a body mass index of 30 or more. Childhood obesity has tripled in the past 30 years. Adult-onset diabetes is now often referred to simply as "Type 2," because so many who have it are young.

But pizza is a tiny piece of a huge public health discussion we need to promote.

"Focusing on pizza, or tomato paste, is really looking at the needle instead of the haystack," said Felicia Busch, a Twin Cities registered dietitian and former spokeswoman for the American Dietetic Association.

"We need to tell people what they can eat more of, or how to take something marginally nutritional and make it better. Restricting available choices is probably going in the wrong direction."

Busch, the mother of three and author of the book "The New Nutrition," thinks schools too often get a bad rap. She's seen plenty of progress in lunch programs, especially around pizza.

"Schools have come a long way," she said, "such as adding whole-grain crusts, reduced fat cheese and vegetable toppings instead of fatty meats. Pizza can be one of the most nutritious foods," she said.

Just don't tell the kids.

But it's outside the school lunchroom where serious work awaits to turn a dangerously unhealthy generation around. Few school districts offer daily physical education; others have cut back on recess. Some school districts prohibit kids from walking or biking to school because of safety or liability concerns. That concerns Busch.

"That's the age group that is building foundational habits for life," she said.

Things are a challenge on the home front, too. Many suburban neighborhoods have no sidewalks, discouraging regular walks. Kids spend too much time on their home computers or in front of the TV. Harried parents, many working the second or third shift to make ends meet, rarely can enjoy the luxury of sitting down to a healthy family dinner.

And we cannot ignore economic inequities when it comes to healthy eating. What's cheap? Potato chips are cheap. Pop is cheap. Lean meats, fresh vegetables and fruits in season are hard for many to afford. This is why I constantly sing the praises of Minnesota's abundant farmers' markets, which level the playing field around nutritious eating.

I know. It's tempting to just bury our heads in that last piece of Thanksgiving pie. But take heart. Slow and steady is the best approach to changing habits in the long run.

A nice long walk of 30 to 60 minutes a day with your kids works well, too. Put on snow shoes if you need to.

If you're concerned about your child's school lunches, pack them with your kid, or talk to your school's food service director about adding healthier ingredients to foods kids will eat.

If you can't eat dinner together, eat a healthy breakfast together. Add extra vegetables to box mixes and whole grains to soups.

You might also check out First Lady Michelle Obama's website, www.letsmove.gov, filled with exercise plans and healthful recipes. Here's one that looks really delicious:

It's called "The White House Kitchen Garden Fall Harvest and Grilled Garden Pizza," (www.startribune.com/a841). Enjoy.

gail.rosenblum@startribune.com 612-673-7350