Lack of sleep makes children fat

Insufficient sleep time may be hazardous
to health of childrenMajority of people, including children, experts say, need about eight hours of sleep each night to fully recover from the stress of the day. However, when children do not sleep sufficiently, experts warn that it could lead to their developing weight problems later in life, writes Sade Oguntola.

Since the past decade, researchers have been studying sleep based on today’s reality: a world where increasing numbers of people are increasingly unwilling or unable to sleep for the day.
Sleep needs vary slightly, but the vast majority of people, experts agree, need just about eight hours of sleep each night to fully recover from 16 hours of being awake. Without enough sleep, the cost in reduced memory, focus, concentration and reaction time is enormous.

The effects of sleep deprivation are also noticed in children and a new study has warned that when children do not get enough sleep, they are more likely to become obese when they grow up. Obesity is a health problem that has been linked to several health problems in adulthood such as diabetes, infertility, cancer and even hypertension.

The Harvard study found that babies and toddlers who sleep fewer than 12 hours daily are at greater risk of being overweight in preschool, startling evidence that the link between sleep and obesity may affect even very young children.

Most of the children that were found to sleep less than 12 hours and who view two hours or more of television a day have a 16 per cent chance of becoming overweight by age three, said the study published in the April issue of Archives of Paediatrics & Adolescent Medicine, a professional journal published by the American Medical Association.

The US-led study team identified 915 mother-infant pairs from a long-term study of the effects of diet and other lifestyle factors on maternal and child health. Starting from when the babies were six months old until age three, the mothers gave reports of their babies’ sleep habits and TV viewing, as well as direct measures of the children’s height, weight and skin fold thickness.

The researchers combined the sleep answers to find an average pattern for each child during the first two years of life. They found 586 of the children slept an average of 12 or more hours a day and 329 of the children slept less than that.

Among the long sleepers, 7 per cent were obese at age 3. The short sleepers fared worse. Twelve per cent of them became obese 3-year-olds. Adding TV to the picture, 17 per cent of those who slept less than 12 hours a day and watched two or more hours of television a day were obese by the time they were three.

The researchers took into account other risk factors for obesity, including TV viewing, and still found the children who slept fewer than 12 hours a day had a doubled risk of being obese at age 3 than the other children. Elsie Taveras, assistant professor at Harvard Medical School department of ambulatory care and prevention, and lead author of the study, said:

“Mounting research suggests that decreased sleep time may be more hazardous to our health than we imagined. We are now learning that those hazardous effects are true even for young infants.”

That is not the only problem. The journal also published research by Dr Alice Gregory of the University of London and colleagues, who collected sleep data on 2,076 children who were aged four to 16 years old at the beginning of the study. It showed that children who sleep less might be more likely to report symptoms of anxiety, depression and aggression later in life.

The research found that lack of sleep equally prevents the body from producing sufficient quantities of a hormone that suppresses the appetite. The experts looking at young children said those who had problems sleeping were almost twice as likely to be obese young adults as those who had little trouble.

Dr Abdullah Al Mamun, of the University of Queensland in Brisbane, studied 2,500 children from birth to age 21. Analysis revealed that poor sleep quality when very young was a significant risk factor for obesity in early adulthood, regardless of lifestyle or diet. Only 13 per cent of those who rarely had irregular sleeping habits at two and four were obese. However, this rose to 23 per cent among those who often had problems sleeping.

According to Dr Mamun’s research, the lack of rest means the body secretes less of the appetite suppressant leptin and increases levels of the appetite stimulant ghrelin. In addition, too little sleep may also disrupt the metabolism and change the way the body reacts to insulin, a hormone linked to the speed at which the body puts on fat.

Writing in the American Journal of Epidemiology, Dr Al Mamun said there were three possible reasons why children who struggled to sleep might grow fatter. “First, children who sleep less have more time in which to eat. Second, lack of sleep results in tiredness and less physical activity during the day. This causes less energy expenditure than energy intake. Or less physical activity may result in reduced sleep quality or duration.”

As well as affecting the hormones regulating-appetite, he said reduced sleep could also mean that lower levels of the growth hormone somatotrophin were released. This hormone helps break down body fat.” Meanwhile, Dr. Tunde Oni, the medical director at The Clinic on the Hill, Ikolaba, Ibadan, said it does not really make a sense to say that lack of sleep may predispose to being fat and that if such is noticed there may be a reason for this to be investigated appropriately.

He said that weight gain in children is usually due to the amount of food consumed, hygiene and the genetic nature of the individual, stating that usually when an individual is unable to sleep there is the temptation to eat more and this will subsequently accumulate as fat. While the condition of the place the baby is supposed to sleep may affect the quality of sleep of a child, say in about 10 per cent, he said, “Weight gain is more of genetic and calorie intake in an healthy child in our community. To say weight gain has to do with the quality of sleep a child has cannot be said to be true in this environment. “

“The main message for parents is that there has to be regularity in sleep in children. It’s very important to maintain a schedule,” said Dr. Michelle Cao of Stanford University’s sleep disorders clinic. Genetics may play a role in sleep and a person’s genetic makeup may limit how much sleep duration can be improved upon, but experts say the more active children are in the day, the better they will sleep at night. So parents who rely on day care should make sure their toddlers have plenty of time to run, jump and play.

Meanwhile, the American Academy of Sleep Medicine advises parents of children with sleeping problems to do the following:

• Interact with youngsters at bedtime

• Prevent them from watching television or playing computer games for long periods before bedtime

• Ensure a relaxing environment in the bedroom

• Follow a consistent routine, with 10-30 minutes set aside to prepare for bed

• Stop them from watching television programmes or playing computer games that are inappropriate for their age

• Make sure they do not fall asleep while being held, rocked or fed

• Avoid drinks or food containing caffeine or medicines that contain stimulants