A study found that teenagers who sleep less than seven hours per night are up to 70% more likely to suffer from obesity or overweight. Additionally, getting between seven to eight hours also increased the risk of weight gain by up to 29% compared to those who got a full eight hours. Spanish researchers who conducted the study emphasized why teenagers should sleep for at least eight hours. Lack of sleep can lead to the production of the hunger hormone ghrelin, causing them to eat more, which increases their risk of obesity.
The study, which involved over 1,200 children aged between 12 to 16 years, measured their sleep over a week and compared it to their Body Mass Index (BMI). It found that 14-year-olds who slept less than seven hours a night were 72% more likely to have a BMI over 25 compared to those who slept more than eight hours. Researchers advised parents to "be good role models" by enforcing strict sleep schedules to avoid exposing their children to the risk of heart disease due to weight gain.
This comes amidst a widespread obesity epidemic among children, with one in five children in England being severely obese by the time they start primary school. Childhood obesity has reached "unprecedented levels" during the COVID pandemic, as children stayed home unable to run around playgrounds. The National Health Service (NHS) recommends that teenagers get between seven to 11 hours of sleep each night for their physical and mental development. Previous studies have also shown that lack of sleep can lead to a range of health problems later in life, including high blood pressure, dementia, and diabetes.
The latest research was presented in abstract form at the 2022 European Society of Cardiology Conference. The researchers used data from a study conducted on 1,229 secondary school children in Spain in 2019 to determine how sleep affected their weights. The children were divided into groups of 12, 14, and 16 years old. Their BMI was recorded to see if they were underweight, of normal weight, overweight, or obese, taking into consideration age, height, and sex. Overall, 27% of 12-year-old children, 24% of 14-year-olds, and 21% of 16-year-olds were overweight or obese.
Researchers also measured waist circumference, blood pressure, cholesterol, and blood sugar levels to assess their overall health. Teenagers were given sleep trackers to wear on their wrists for a week to measure their sleep. Only 34% of 12-year-olds slept at least eight hours, while the numbers were lower for 14-year-olds (23.4%) and 16-year-olds (19.4%). Researchers noted that boys and children from ethnic minority families tended to sleep for shorter periods.
After adjusting for exercise and diet, researchers found that 12-year-olds who slept less than seven hours a night were one-third more likely to be overweight or obese compared to those who got at least eight hours. Children aged twelve who slept between seven to eight hours were one-fifth more likely to fall into this category. Both groups were more prone to having large waistlines, high blood pressure, cholesterol, and blood sugar levels.
Though researchers did not detail how lack of sleep leads to obesity, previous studies have shown that insufficient sleep can sap energy throughout the day, making individuals less likely to exercise and more likely to snack. Parents can set a good example by having a consistent sleep time and reducing screen time in the evening. Chloe MacArthur, a cardiac nurse at the British Heart Foundation, stated, "Getting enough sleep is crucial during adolescence as it supports healthy growth as well as good physical and mental health. However, teenagers should not only prioritize good sleep at night, as getting adequate sleep is vital for our overall well-being and maintaining good heart health throughout life."
