"This food wouldn't spoil in that location," the computer-generated voice said. "But the quality of food could be affected, or you might be using space in your freezer unnecessarily."
Another lesson learned from the Fantastic Food Challenge, a package of four computer games designed to teach people who get nutrition aid such as federal food stamps how to make better use of their food.
Because so many young adults played such games as kids, they ought to be able to learn more easily from them, too, said the project's director.
"We wanted to create a game that didn't just feel like you were learning something," said Brian Winn, an assistant professor of telecommunication, information studies and media at Michigan State University in East Lansing.
The player feels like a contestant in a marathon of futuristic television game shows that also happen to give instruction about how to buy food at the lowest cost, store it properly and prepare healthy meals, Winn said.
One game is called Store It Safe. It involves placing baked beans, tortillas, frozen chicken and other virtual groceries into a cartoon-drawn freezer, cupboard or refrigerator.
In another game, a version of Concentration, players turn over blank cards that flash a food and a menu item made with that ingredient, then try to remember which card had the milk that matches the macaroni and cheese. The on-screen opponent is an sore-loser robot that blows steam out of its ears when it guesses wrong, but which gets better as the game becomes more difficult.
In the Great Meal Deal, players test their knowledge of the five food groups (milk, meat, fruit, vegetables and grains) by dragging randomly generated bananas, peanuts, applesauce and other items into the correct group.
Players in the Price Makes Sense have to use their math skills to figure out the best food deal; for instance, that six servings of eggs at $1.20 is cheaper per serving than five servings of chicken at $2.00.
The program is being distributed to employees in Michigan's extension offices who teach food aid recipients how to be efficient shoppers. So far, they seem to like it better than the usual brochures and charts, said Gayle Coleman, the extension service's interim state program leader for family consumer science.
Food stamp users are not the only people who can benefit from these kinds of projects, said Melinda Johnson, a spokeswoman for the American Dietetic Association. But the poor may need the help more because they have fewer options, she said.
For example, people in every income level have to squeeze healthy meals into busy lives, although those who are better off do not feel the budget pinch when they buy prepared meals at the supermarket, Johnson said.
Researchers also have tried computer games to improve eating habits for about 1,600 fourth graders in Houston. They played a medieval-themed game called Squire's Quest, developed by researchers at Baylor College of Medicine's Children's Nutrition Research Center.
Kids win by getting promoted from squire to knight. But the real goal is to get them to eat more fruits and vegetables.
In the game, players advanced by learning such things as how to talk a parent into serving orange juice for breakfast and they gained negotiation skills by accepting pineapple juice if that was available instead, said Tom Baranowski, lead scientist in the game's development.
"We do role-playing to encourage the kid to go home and ask Mom," he said.
By Ira Dreyfuss