Not getting enough sleep or spending less time in rapid eye movement (REM) sleep, could cause children and teens to suffer from obesity, as per a new study.

According to lead researcher Xianchen Liu and his colleagues, in just 30 years the obesity rate has tripled among children aged 6 to 11 years, with about 17 percent of U.S. adolescents becoming overweight or obese.

An imbalance between calorie intake and energy expenditure from physical activity, has been known to lead to obesity. Other factors affecting the balance have however not been observed.

Liu, M.D., Ph.D., of the University of Pittsburgh School of Medicine Department of Psychiatry and Western Psychiatric Institute and Clinic of the University of Pittsburgh Medical Centre, and colleagues, conducted a number of studies on 335 children and adolescents age 7 to 17 years (average age 10.8).

Their studies discovered that there is an association between fewer hours of sleep and higher body mass index (BMI) in both adults and children.

A study of the participants' sleep pattern was monitored through polysomnography, for three consecutive nights. Their total sleep time was assessed, time spent in REM, the time it took them to fall asleep and other variables. Their weight and height were measured to calculate BMI.

It was discovered that a total of 49 participants (14.6 percent) were at risk of becoming overweight and 45 (13.4 percent) were overweight.