Sharing a cell phone or other device with a child often keeps them entertained, but health experts say too much exposure could be bad for their health.

According to a recent study published in JAMA Pediatrics, screen time triples between the ages of one and three years old in the U.S., meaning a one year-old will go from watching 53-minutes of content a day to more than 150 minutes by age three.

Dr. Rishma Chand urges parents to monitor how much time kids are planted in front of a screen: “Screen time becomes a problem when it replaces things kids should be doing at youth — playing sleeping, talking, having real-time interactions. That’s when screen time becomes a problem.”

Chand says it can also have a negative impact on a toddler’s brain activity as kids need face to face engagement, especially in the early years: “Most of the brain development happens by the age of two and so American Academy of Pediatrics has recommendations… Under 18 months of age, there is no screen time recommended with the exception of video chatting.”

Health experts recommend children under 18-months avoid screen-time altogether — unless video chatting. Kids 18-24 months should only view quality media that’s educational. Ages 2-5 should be allowed up to one hour of screen time a day. Parents with kids 6 and older need to set limits.

Researchers say there is a difference between watching television and mobile devices.

“TV and video games shown to have worsening academic performance compared to tablets, which can be beneficial because there’s a lot of educational tools and phones, have a lot of apps that are interactive,” says Chand.

Experts say screen time could also disrupt the quality and quantity of sleep, so try to avoid it late at night.