Children under five must spend less time sitting watching screens if they are to grow up healthy, according to new guidelines issued by the World Health Organization (WHO).They must also spend less time restrained in strollers and seats, get better quality sleep, and have more time for active play, the guidelines say.“Achieving health for all means doing what is best for health right from the beginning of people’s lives,” says WHO Director-General Dr. Tedros Adhanom Ghebreyesus. “Early childhood is a period of rapid development and a time when family lifestyle patterns can be adapted to boost health gains.” The new guidelines on physical activity, sedentary behavior, and sleep for children under five were developed by a WHO panel of experts. They assessed the effects on young children of inadequate sleep, and time spent sitting watching screens, or restrained in chairs and strollers. They also reviewed evidence around the benefits of increased activity levels. “Improving physical activity, reducing sedentary time and ensuring quality sleep in young children will improve their physical, mental health and well-being, and help prevent childhood obesity and associated diseases later in life,” says Dr. Fiona Bull, programme manager for surveillance and population-based prevention of noncommunicable diseases, at WHO. Bring back playFailure to meet current physical activity recommendations is responsible for more than 5 million deaths globally each year across all age groups. Currently, over 23 percent of adults and 80 percent of adolescents are not sufficiently physically active. If healthy physical activity, sedentary behavior, and sleep habits are established early in life, this helps shape habits through childhood, adolescence, and into adulthood.“What we really need to do is bring back play for children,” says Dr. Juana Willumsen, WHO focal point for childhood obesity and physical activity. “This is about making the shift from sedentary time to playtime, while protecting sleep."The pattern of overall 24-hour activity is key: replacing prolonged restrained or sedentary screen time with more active play, while making sure young children get enough good-quality sleep. Quality sedentary time spent in interactive non-screen-based activities with a caregiver, such as reading, storytelling, singing and puzzles, is very important for child development.The important interactions between physical activity, sedentary behavior and adequate sleep time, and their effect on physical and mental health and well-being, were recognized by the Commission on Ending Childhood Obesity, which called for clear guidance on physical activity, sedentary behavior, and sleep in young children. Applying the recommendations in these guidelines during the first five years of life will contribute to children’s motor and cognitive development and lifelong health.