When his third-grade son was handed a doughnut and soda after a football game, University of Minnesota assistant Prof. Toben Nelson was dismayed -- but not surprised. He also has coached kids who show up to practice with bags of fast food.

For two years, Nelson has been working on the Healthy Youth Sports Study. One finding in the continuing study is that almost half of kids 12 to 17 who are overweight participate in sports. Youths who engage in sports eat more fast food and sports drinks, adding up to more calories than their non-participating peers.

Three out of four kids participate in some sort of organized sport, according to Nelson.

"Lots of attention in obesity prevention has focused on school, preschool and after-school programs," said Nelson, who previously worked with the Harvard Prevention Research Center on a project to help the YMCA improve nutrition and physical activity in after-school programs. "It seemed to me that youth sport was the next major area to focus, since kids spent lots of time in those settings."

The recipe for overweight athletes quickly became clear to researchers: Game and practice times frequently make dinner an on-the-run affair, and kids are idle for half of a typical practice, according to a San Diego State study.

"We've heard from parents that it's no big deal if the kids are eating junky fast food, because they just ran around for an hour," Nelson said. "But that's an overcompensation."

After conducting focus groups, Nelson and registered dietitian Michelle Parke developed guidelines for parents, coaches and leagues.

The good news is that the extensive advice is welcome: "Parents end up competing with each other to bring the 'best' snack, but they hate it because it's not consistent with what they're trying to do at home," Nelson said. "They feel powerless to try and change it. They want help from the leagues."

Healthy eating needs to be valued and facilitated in sports environments in order to accommodate time pressures and convenience, Parke said.

Healthy food can be convenient, she and Nelson insist, but it does take planning. Parents need to prioritize, they said, committing to doing advance work to avoid the last-minute rush to get dinner before practice or game time.

But the onus isn't just on parents. Leagues, organizations and coaches can help change the landscape. Older kids might be more willing to hear nutrition advice from coaches and older kids than parents.

Take a typical parent-staffed concession stand. Instead of assigning a parent to run to Sam's Club and get whatever they think spectators and participants will buy -- usually candy and junk food -- carefully think out what to offer: frozen grapes in the summer, for example, string cheese, baby carrots, pita and hummus.

Find out more at www.startribune.com/a845.

Sheila Mulrooney Eldred is a Twin Cities freelance writer.