The World Health Organization classifies around 400 million people as obese, 20 million of them under the age of five. The condition raises the risk of diseases like type 2 diabetes and heart problems. Recent research has found a connection between sleeping hour during childhood and obesity in adulthood. Children who do not get proper amount of sleep have more chances of becoming obese in adulthood.

Research team from the Dunedin Multidisciplinary Health and Development Study at the University of Otago, in Dunedin, New Zealand reached this conclusion after following 1,037 children born in Dunedin between 1972 and 1973 up to the age of 32. The scientists noted the subjects’ time in bed every two years between ages 5 and 11 and measured body weight at age 32. When the participants were 5, 7, 9 and 11 years old, their parents reported on their usual bed time and wake-up time. Researchers found that as childhood sleep time declined, adulthood body mass indexdefine (BMI) climbed.

Lead researcher, Erik Landhuis said that everybody knows the importance of a good night’s sleep and various studies have shown that sleep-deprived adults and children are at greater risk of being overweight but this was the first ever study conducted to show the potential implications for obesity in the adulthood from lack of sleep during childhood.

He added: “It is not clear why lack of sleep might lead to weight gain, but experimental studies have shown that sleep deprivation may disrupt the hormonesdefine that regulate appetite. It has also been suggested that tired kids may simply have less energy and are therefore less active.”