The study followed 591 children from birth to seven years old and assessed their sleep duration at different stages. Results link inadequate sleep length to an increase in body fat. Children who slept less than nine hours were likely to have a significant increase in their body fat percentage and also become more prone to emotional and behavioral problems, than those who slept more than nine hours. These associations remained strong and were not affected by adjustment for physical activity or dietary consumption. Similar results were published in November 2007 by another study from the University of Michigan where less than nine hours of sleep each night placed children at an increased risk of obesity.

Lack of sleep has already been linked in earlier studies to mental and behavioral problems in children. In fact, a chronic reduction of just one hour of sleep per night in early childhood has been shown to affect cognitive performance at school age. These findings were recently confirmed by another study of over 1,400 children in Quebec, Canada.

Some scientists compare the effects of sleep disorders in children to that of lead on the mental capacity and IQ, as it can impair the child's learning capability and vocabulary.

For infants, sleep deprivation or fragmentation is also linked to an increase likelihood of SIDS (Sudden Infant Death Syndrome), and sleep apnea was much more common in sleep-deprived children. Equally troublesome though frequently misunderstood by many parents, is that such children often develop a high arousal threshold, either auditory or respiratory; this problem results in the child having difficulty waking up when in danger, and is not to be confused with one being a sound-sleeper or being very adaptable to changing environments.

The National Sleep Foundation recommends the following basic daily sleep requirements for children, adolescents, pre-teens and teens:

Preschoolers: 11-13 hour

Elementary school students: 10-12 hours

Pre-teens: 9-11 hours

Teens: 8-9 hours

Establishing a nightly bedtime ritual can ease the process of putting the child to sleep. Parents should guide children to follow a bedtime routine, where the child can wind down away from the stimulation of television, computers, electronic games, and cell phones. Lighting in the bedroom should be dimmed during the relaxation phase; reading a bedtime story or playing soft music in the background works well also for many parents. Other environmental tools, such as certain magnetic mattresses and comforters, could be used to promote relaxation and better restfulness for all children.