Insufficient sleep and exercise linked to obesity in Chinese pre-school children
As paediatric obesity is now a major public health problem in China, researchers at Yale University and China's Central South University conducted a study to assess the link between obesity in pre-school kids in Changsha City and their sleep and physical activity.
The study involved 112 pre-schoolers aged three to six, with BMI used as an indicator of obesity.
Their caregivers reported their sedentary duration, and their physical activity and sleep were recorded by fitness bracelets.
Growing up… sideways
The researchers reported that the prevalence of overweight and obese children was 15.2% and 9.8%, respectively.
The children took between 11,111 steps a day on weekdays and 14, 468 steps a day on weekends, though this difference is not statistically significant.
However, the amount of time spent daily on vigorous physical activity on both weekdays and weekends was significantly different, with overweight children exercising for 20.5 to 52.1 minutes daily and obese children exercising for 10.3 to 25.6 minutes.
In addition, 10.7% of the overweight children and 50.9% of the obese children used screens for over two hours daily.
They also slept for significantly longer on weekends (8.3 to 9.2 hours) than on weekdays (8.1 to 8.8 hours), with a higher proportion falling asleep before 10 PM on weekends (26.8%) than on weekdays (15.2%).
Furthermore, their BMI was found to be positively correlated with their parents', and monthly household income was inversely related to children's BMI.
Boys were also more likely to have a higher BMI than girls, with obese children more likely to sleep less compared to children of normal weight.
Weight limits
However, the study's cross-sectional design did not determine any causation between sleep duration and obesity.
In addition, the sample size was small, and the researchers did not take into account other factors, such as weight changes and dietary history, that may have influenced the results.
They further stated that it was possible that the fitness bracelets could have had measurement errors.
They then concluded: "Chinese preschool children had a high prevalence of overweight and obesity, and demonstrated poor sleep and physical activity habits.
"Additional research is necessary to further explore the mechanism of influence among overweight and obesity, sleep and physical activity for young children in China."
Source: International Journal of Environmental Research and Public Health
https://doi.org/10.3390/ijerph15030527
"The Relationship between Obesity, Sleep and Physical Activity in Chinese Preschool Children"
Authors: Meimei Ji, et al.
