Going to bed early can prevent teenage obesity in children. Recently Dr Sarah E Anderson MD, PhD, at the University of Ohio State, has found that children who have a bedtime of 8 pm are far less likely to gain excessive weight during the teenage years than children who stay up late i.e., well past 9 pm. Thus an early bedtime can be the key to preventing obesity in teenagers.

Dr Anderson said, “There is a great deal of evidence linking poor sleep, and particularly short sleep duration, to obesity, and it’s possible the timing of sleep may be important, above and beyond the duration of sleep.”

Over the past 30 years childhood obesity has more than doubled, while teenage obesity has quadrupled in the US. In 2012, more than 21% of teenagers i.e., one-third of the population group, between the ages of 12 to 19, were reported obese. The rate has increased substantially from the mere 5% in 1980s. Obesity in the US is defined by excessive body weight fat based on height and believed to be the result of metabolic imbalances, influenced by various factors genetic, behavioral and environmental.

The study published in the Journal of Pediatrics analyzed data from 977 children who were part of the study of Early Child Care and Youth Development. The children’s bedtimes were recorded at the age of 4½ years old and additional data on height and weight was taken at the age of 15 years old. The study was carried out back in 1991 on children born at the time and consisted of a total of 1,364 participants.

Only 10% of the children who went to bed early i.e., at 8 pm, had teenage obesity. Meanwhile, 16% of children who went to bed after 8 pm and before 9 pm were found to be obese. Likewise, 23% of the children who went to bed after 9 pm were obese. It was concluded the rate of teenage obesity consistently increased in children as their bedtime was delayed. The results were adjusted for other factors influencing obesity such as socioeconomic status, maternal obesity and parenting style, but still the risk of developing obesity was greater in children who stayed up late. Although the study does not prove bedtime is a major cause behind obesity, it does show a strong link between the two.

“This provides more evidence that having an early regular bedtime and bedtime routine for young children is helpful,” said Anderson.

Health experts have been stressing the importance of a good night’s sleep for a long time. This is not the first time a link between sleeping pattern and body weight has been established. Doctors advise that a person should at least sleep for 7 to 8 hours every day to maintain a normal and healthy body weight, and evidence pointing out towards the lack of sleep may be the reason behind why obesity has been mounting. The sleeping duration of the American society has been decreasing since before the turn of the 21st century. The tendency to stay up late has gradually increased over the decades. By 1998, only 35% of Americans were believed to be getting a good 8 hours of sleep and by 2005 only 26% of adults were getting enough sleep to be considered healthy. Such facts assert the conviction that lack of sleep is a major cause of the current obesity epidemic in the US.

In 2015, the Project Viva carried out on 915 children found that infants with less than 12 hours of sleep were twice at the risk of becoming obese by age 3. Similarly, a British research carried out on 8,000 children since their birth found that children who only slept less than 10 hours during infancy have a greater chance of becoming obese until the age of 7 years old. Although the evidence is based on observational data, a strong association between sleeping and obesity has been established.

Sleep deprivation and deviations are believed to alter eating patterns. Getting less sleep during the night may disturb the hormonal balance of the body and subsequently lead to an increased appetite. Sleep deprived people have an increased level of the appetite-stimulating hormone ‘ghrelin’ along with lower levels of the satiety-inducing hormone ‘leptin’. People with less sleep time are also more prone to eat out and have irregular meal patterns.

Sleep deprived people who go to bed late tend to be tired during the day and less likely to work out compared to people who go to bed early and rise up early. The body temperature of people with less sleep is also affected and found to be lower which in turns decreases the energy expenditure of the body. All in all, maintaining a healthy sleeping pattern since childhood has the potential to prevent obesity.