MANHASSET, Long Island -- We pay close attention to what our kids eat, but what about how much time they spend staring at a screen?
There is growing evidence that excessive screen time on smartphones, tablets and handheld games is not good.
5-year-old Dean Kozinn is perfectly happy playing ball with his brother, Jack, and a friend in Manhasset, but when they're playing on an iPhone or iPad that usually ends in a fight.
"He just goes into a full temper tantrum," said Julie Kozinn, a mother of two.
In fact, Dean actually runs away at the very suggestion that he go outside to play.
That's the very same boy who was just happily playing with no device in hand.
"Lately we've pulled it completely because they don't know how to not be on it," Kozinn said.
Studies are helping us understand why. Research shows rapid dopamine being released into in the brain while kids play certain video games.
It's not unlike the way any addict would feel after a fix, but there's more. Experts say this world is a deliberately controlled one, where a kid can be the master, and that makes it harder to go back to the real world.
"Because the real world, as it were, is much less predictable, much less controllable, than those video games are," said Dr. Michael Rich. The "Mediatrician."
No two kids are exactly alike, so experts say there's really not one uniform way of regulating your kids' screen time. One thing they say we can all do as parents is to look to our own behavior when spending time with our kids.
Here's something else, a written contract setting rules limiting usage.
Dawn Ader who runs workshops for parents and kids has one in her home.
"Refer to the paper; this is what we agreed to. It's in print, you signed, can't go back on it," said Ader, "Girls Athletic and Life Skills" (GAALS) USA founder.
Experts say it may not work for every family, but in the end, experts say setting limits and teaching kids a little self-awareness could go a long way.