Many families are a bit more lax when it comes to screen time during the summer months, but with school nearly back in session a Mayo Clinic expert is cautioning parents that too much time behind a tablet or smartphone can be unhealthy.

Pediatrician Dr. Angela Mattke said how much is too much depends on the child’s age. “The recommendations are really to minimize screen time in children before age 2,” explained Dr. Mattke. “Between ages 2 and 5, we would recommend you keep the screen time to one hour or less per day. And in children that are older than 5, we recommend trying to minimize a recreational or enjoyment-related screen time to two hours or less per day.”

Two hours or less a day applies to teens as well but Mattke said those recommendations do not include educational-related screen time.

“I would use the screen time as a reward,” she said. “Try not to use it as a punishment, but if you’re using it as a reward, it’s something they’re earning throughout the day for good behavior.”

In limited amounts, the social aspect of screens can help teens feel connected, Dr. Mattke said. Too much screen time may interfere with sleep, increase the risk of depression, and increase the risk of obesity.

“There is a research study recently that showed for every hour per week increase of screen time, they saw increases in the BMIs [body mass indexes] of preschool-age children.”

She said the best way to help kids manage screen time is to be aware and communicate with them.