Children Who Sleep Less Are 'at Risk of Obesity'

The duration of your child's sleep can vary, depending on the time of day and year. But parents, please note -- the less your kid does shut-eye, the more likely he or she is to become overweight and have frequent mood swings.

A team of international researchers has carried out a study and found that children who do not get enough nightly sleep are at risk of becoming obese as sleep restriction leads to hormonal changes in the stomach as well as in fat cells that trigger increased appetite.

"Sleep is important for health and well-being throughout life. Our results show a strong effect of short sleep duration on risk of obesity even when levels of daytime activity are adjusted for.

"This effect was independent of physical activity or television watching. Attention to sleep in childhood may be an important strategy to reduce the obesity epidemic," lead researcher Prof Ed Mitchell of the University of Auckland in New Zealand wrote in the American journal 'Sleep'.

The researchers came to the conclusion after focusing on a group of nearly 600 children, all aged seven.

The team assessed the shut-eye duration of the kids by actigraphy (a non-invasive method to study sleep-wake patterns and cardiac rhythms) at four stages of their young lives - at birth, at one year, at three-and-a-half years and at seven years.

A range of other measurements such as height, weight, body mass index (BMI) and body fat levels were also taken for each participant. A BMI of 20 to 25 is considered normal, 25 to 30 overweight, and over 30 obese.

The participants who got fewer than nine hours of per night sleep were found to be nearly three times more likely to be overweight or obese and to have a 3.34 per cent increase in body fat than those who slept for longer.

Children who got less than average sleep were also found to be more likely to develop behavioural changes.

According to the researchers, the lack of sleep leads to increased production of ghrelin, a hormone produced in the stomach, and reduced release of the hormone leptin in fat cells, which stimulate appetite, leading to obesity and behavioural changes in children.