The World Health Organization (WHO) recently issued guidelines on screen time, physical activity, and sleep for children from birth through age 4. The guidelines were issued in response to a 2016 report from the WHO’s Commission on Ending Childhood Obesity, which linked rising rates of childhood obesity worldwide to a decline in physical activity, increased screen time, and inadequate sleep for young people. According to the report, an estimated 41 million children around the world who were younger than 5 years of age were overweight or obese.

Although the American Academy of Pediatrics (AAP) established screen time guidelines for children several years ago, the WHO guidelines mark the first time that the international health organization has provided a framework to help children develop healthy habits early in life.

Here’s what the WHO recommends for children of different ages:

Infants (less than 1 year old):

• Screen time is not recommended for infants
• Infants should engage in interactive, floor-based physical activity several times a day, with at least 30 to 60 minutes of “tummy time”
• Infants up to 3 months old should get at least 14 to 17 hours of quality sleep in a 24-hour period, including naps. Infants 4 to 11 months old should get 12 to 16 hours of quality sleep in a 24-hour period, including naps.

Children 1 to 2 years old:

• Screen time is not recommended for 1 year olds
• For 2 year olds, limit screen time to 1 hour or less a day. Caregivers or parents should co-watch content with the child
• Engage in a variety of activities to get at least 180 minutes (or 3 hours) of physical activity each day
• Establish regular sleep and wake-up times for 1 to 2 year olds. They should get 10 to 13 hours of quality sleep in a 24-hour period.

Children 3 to 4 years old:

• Limit screen time to 1 hour or less a day. Caregivers or parents should co-watch content with the child
• Engage in a variety of activities to get at least 180 minutes (or 3 hours) of physical activity each day, including at least 60 minutes of moderate-to-vigorous activity
• Establish regular sleep and wake-up times for 3 to 4 year olds. They should get 10 to 13 hours of quality sleep in a 24-hour period

For all age groups, children should not be restrained in a high chair, stroller, or car seat for more than 1 hour at a time in order to avoid prolonged sedentary time.

“As smartphones and mobile devices have become more affordable, more available, and more widely used around the world, children across the globe are becoming more sedentary—swapping active play time for screen time,” said Jay D’Orso, MD, pediatrics and internal medicine, Western Connecticut Medical Group. “More screen time and less physical activity—especially at a young age—can lead to unhealthy habits that place kids at an increased risk of developing childhood obesity. Studies have shown that childhood obesity can lead to type 2 diabetes at a young age and increase a child’s chances of developing other health issues later in life, such as heart disease.”

In addition to increasing the risk of health problems, Dr. D’Orso said that excessive screen time limits the learning and socialization opportunities that are available to young children through creative, unstructured play with parents or peers.

“There is data that shows that children learn best through unstructured play—such as playing with blocks and reading or looking at books,” said Dr. D’Orso. “In addition to helping kids develop motor and cognitive skills, engaging in unstructured play with a family member, caregiver, or another child also can help children learn how to manage social interactions.”

Dr. D’Orso said that by following recommended guidelines for screen time, physical activity, and sleep, children can develop important receptive and expressive language skills, motor and cognitive skills, improve physical and mental health, and promote lifelong well-being.