Pediatricians warn sleep is the ignored culprit driving childhood obesity, as a new study shows a direct link between shut-eye and weight gain.
Experts also warn just a few nights of poor sleep put children at an increased risk of developing obesity-related cancers such as liver and ovarian cancer.
The rate of childhood obesity in the US has more than tripled since the 1970s, with one in five children being obese, according to the Centers for Disease Control and Prevention.
Research shows poor sleep causes children to eat more and affects their metabolism.
The National Sleep Foundation recommends nine to 11 hours of sleep for children aged six to 13 years old, eight to 10 hours of sleep for teenagers, and seven to nine hours of sleep for people aged 18 and older.
For the study, researchers from Virginia Commonwealth University’s Massey Cancer Center tracked the sleep-wake cycle of 120 children between the ages of 6 and 19 years old for at least five days.
‘Childhood obesity very often leads to adult obesity,’ said lead study author Dr Bernard Fuemmeler. ‘This puts them at greater risk of developing obesity-related cancers in adulthood.’
During which, researchers observed the children’s eating habits.
They had the kids complete a ‘eating in the absence of hunger test’— children ate a meal and reported when they were full — and then analyzed that data to track how much food children are once their appetites were satisfied.
Dr Fuemmeler and his team found that fewer hours of sleep was associated with a higher body mass index z-score (BMI z-score), the measure of body fat based on a child’s age and sex. Each additional hour of sleep with linked to a .13 decrease in BMI z-score, and a 1.29 centimeter decrease in waist circumference.
Disrupted sleep patterns were also linked to a larger waist, while children who were active earlier in the day had a higher intake of calories once they reached the point of satiety.
The sleep-wake cycle also intertwines with the gut bacteria, and poor sleep could have adverse effects on metabolism.
‘Today, many children are not getting enough sleep,’ Fuemmeler said. ‘There are a number of distractions, such as screens in the bedroom, that contribute to interrupted, fragmented sleep. This, perpetuated over time, can be a risk factor for obesity. Because of the strong links between obesity and many types of cancer, childhood obesity prevention is cancer prevention, in my view.’
This isn’t the first study to suggest sleep quality impacts eating habits and weight.
A 2016 review published in the European Journal of Clinical Nutrition found people who got less than six hours of sleep consumed, on average, 365 calories more per day than those who got six to 12 hours of sleep.
This can add an extra pound to the waistline every week.
Research published in a 2016 issue of Sleep found people who got less than the recommended amount of sleep had a hard time resisting snacks, strengthening the idea that sleep deprivations contributes to weight gain.
It’s worth mentioning that previous studies have also shown that BMI is no longer a good indication of healthy weight.
Findings published in the International Journal of Obesity in 2016 found that using BMI to gauge health miscategorizes more than 54 million Americans as ‘unhealthy.’
Dr Fuemmeler said more research was needed to understand more about the way poor sleep affects weight and whether sleep quality influences weight gain or weight in children affects their sleep.
In addition to weight gain, poor sleep can increase the risk of diabetes, heart disease, and depression, according to the CDC.