Active video games might help people burn more calories than couch-based screen time, but those who play active games tend to undo most of the difference if there's junk food available, says a new study.

Those active gamers tended to eat more calories than they spent dancing, playing hockey, and drumming. They took in an average of 376 more calories than they burned, compared to about a 650-calorie surplus among the inactive groups.

Although small, these differences can mean a lot in terms of energy balance when they are multiplied over days, weeks and years, Dr. Scott Leatherdale at the University of Waterloo in Canada who has studied the effects of video games on energy use but was not involved in the study, told Reuters Health in an email.

"There have been a couple of studies that have shown that TV watching and video playing increase eating, and they increase eating when compared to doing nothing," said Dr. Elizabeth Lyons, who led the study at the University of Texas Medical Branch.

For the new study, Lyons and her team assigned 120 experienced gamers aged 18 to 35, randomly, to watch TV, or to play sedentary or active video games.

They asked them not to eat for 2 hours before the mealtime-scheduled appointments, recorded their appetite level before each session began, and then observed them playing games or watching TV for an hour.

Subjects could watch shows including 30 Rock and The Office, or play games such as Street Fighter IV to Dance Dance Revolution: Universe 2. Chocolate, chips, dried fruits and nuts and sodas were within easy reach.

There was reason to believe that people would eat less if they were playing active games, said Lyons, "because it's physically difficult to eat while you're holding things, and while you're busier."

Yet when Lyons and her team looked at the difference between the groups, they found that while sedentary video gamers ate the most, averaging more than 747 calories during the hour long session, active gamers ate only slightly less, eating 553 calories on average.

The findings, reported in the American Journal of Clinical Nutrition, surprised researchers.

"People will always find a way to eat," said Lyons. "No matter what group they were in they still ate a remarkable amount."

Overall, study participants took in 672 calories during the one hour session, about a third of the daily intake recommended for women by the U.S. Department of Agriculture, and just under a quarter of what's recommended for men.

Men tended to eat more than women, with some men eating in excess of 1000 calories as they played sedentary video games. Heavier gamers ate no more than lighter participants.

'NOT AN ADEQUATE SUBSTITUTE'

For Jacob Barkley, an exercise scientist at Kent State University, the findings still add to evidence that motion controlled games are not a fix for inactivity.

"It's not an adequate substitute for traditional physical activity, like a child going outside and playing in the yard, or an adult going to the gym, but it seems like a better alternative than watching TV or playing a traditional video."

But the study did have some limitations, said Leatherdale.

Barkley agreed. "If you're at home playing this game would you see the same kind of caloric intake? You wouldn't have the buffet of snacks available to you, which increases consumption."

"What we're finding more and more is that TV is uniquely awful for you," said Lyons. So even replacing a portion of your viewing time with an active game could be beneficial, she said.

"But the recommendation is: Get that food away from you! Don't have it on the couch with you, because you'll look up 10 minutes later and it'll be gone."

The study was published in American Journal of Clinical Nutrition, July 3, 2012.