If the children of the video-game generation are overweight, goes the argument, it is hardly for lack of exercise. The problem is, the only part of the body they're exercising is their thumbs.
"The Game Boy only includes my hands," said 6-year-old Max, whom ABC News recruited as a game-tester at the American International Toy Fair in New York City. "You only have to press buttons. And the computer, you just have to click on the mouse and use the keys."
The American Obesity Association reports that 30 percent of the nation's children are overweight and 15 percent are obese. It blames bad eating habits and sedentary lifestyles, and is far from alone in making the complaint.
Toy companies worry when they hear that kind of thing, which is why, at this week's Toy Fair, they are showing off video games that make kids jump, or swing a light saber, or swat flying vegetables -- anything to dispel the image that kids are sitting in front of the screen with their hand controllers, getting fat.
"I was pretty much moving my body," Max said after playing one of the games. "It was good."
There are still plenty of "sit-down-and-move-a-joystick" offerings for hard-core gamers, many of whom are teenagers or young adults. Industry analysts say the first "active-play" games appeared last year, aimed at teens and pre-teenagers. The trend that is showing itself this week is in games aimed at younger children, ages 3 and up.
In some cases, a child becomes a character on the screen. A small camera near the TV set catches the child's movements and matches them to the action in the game.
"We really saw an opportunity in the marketplace because consumers were telling us they want their kids to be more physically active," said Brian Goldner, president of the U.S. toy segment of Hasbro, Inc., which is introducing a gaming system this fall it calls ION.
Will the strategy work? Jimmy Gudmundsen, who reviews children's software for Gannett newspapers and her own Web site, ComputingWithKids.com, said she is not sure.
"I think they have a great novelty factor," she said. "I think, initially, kids will be very drawn to them. Will they stay and play with this gaming system every day? I doubt it."
That may be worrisome to parents who have already invested heavily in Nintendo GameCubes and Sony PlayStations, and are now being asked to shell out more. (The ION platform will cost $119, with an additional $19.99 for individual games.) But the backlash against sedentary games has been strong.
"I think the toy industry is sensitive to the fact that they can help with an issue that is in front of America," said Gudmundsen. "If we can get kids up and moving, that's a good thing."