Each weekday afternoon, Jessica Marquez’s daughters gather in the family’s kitchen to do homework while she makes dinner. Six-year-old Bella and 4-year-old Natalia write, complete workbook activities and spend time talking with their mom, but the rule is: no screens until later in the evening.

“They understand it. They don’t always like it,” Jessica says.

Jessica and her husband made a conscious effort to limit their daughters’ screen time to just 30 minutes a day on the advice of their pediatrician, Dr. Pilar Bradshaw.

“There’s evidence showing that brain development in kids is being tremendously hampered or harmed by too much learning on screens,” says Dr. Bradshaw. “There are fundamental changes in how neurons are connecting as a result of too many hours spent on flat screen learning.”

Between television, smart phones, computers and tablets, children today are constantly connected to screens. According to the children’s advocacy group Common Sense Media, more than 30 percent of children in the United States play with mobile devices while still in diapers and nearly 75 percent of 13- to 17-year-olds have access to a smartphone.

Dr. Bradshaw recommends families set limits on screen time: Teenagers should spend no more than one hour a day in front of a screen, with the exception of schoolwork. For younger kids: 30 minutes or less and none for children under age two. And it’s important to shut off those screens well before bedtime.

“We used to let our children watch TV right before bedtime and it took so long for them to settle down, relax and fall asleep,” Jessica says. “But when we turn the screens off 30 minutes before bedtime and read a book or do something else quiet, they fall asleep much easier.”

Parents are encouraged to engage their children in active play, like board games, or other activities where interaction is face-to-face.

“It’s hard to hear that, in society, we’ve reached a place where kids would rather text their parent downstairs or in another room in the house rather than talk,” says Dr. Bradshaw. “We have to recognize what we’re doing and have real conversations about it, and recognize that for the elementary school kids, we are not doing them a favor by teaching them the alphabet on a smart phone.”

Dr. Bradshaw encourages parents to lead by example: Evaluate your own screen time and cut back if necessary, which can be tough for moms and dads to do.

“It’s kind of like our quiet time,” Jessica admits. “Instead of reading a book, sometimes I go and scroll through pictures on Instagram.”

Screens have their place. They can be useful and entertaining and they should be enjoyed, but it’s important to make the time to unplug.

The American Academy of Pediatrics recognizes that raising children in today’s digital world has changed the playing field for parents. It will take that into account when it issues new recommendations on screen time, which is expected to happen this fall.