Report on Childhood Obesity in China (10): Association of Sleep Duration with Obesity

Objectives To explore the association of sleep duration with obesity among children in urban areas of China.Methods A total of 6 576 children（3 293 boys and 3 283 girls） aged 7-11 years were randomly selected from 36 primary schools in 6 metropolitan cities in China.A 7-day Physical Activity Recall was used to assess the sleep duration and physical activity level.The height,weight,waist circumference（WC） and percentage of body fat（%BF,as determined by bioelectrical impedance analysis technique） were measured by following the standardized operation procedures.The information on demography,lifestyle and eating habits was collected with a self-administered questionnaire from participants and their parents.Results The average sleep duration per night in the children was 9.7 h with the decreasing trends along with the increase of age（P0.05）.The sleep duration was negatively associated with body mass index（BMI） and WC in both boys and girls after adjustment for confounders（β value-0.23 and-0.82 for boys,-0.24 and-0.91 for girls,respectively,P0.01）.However,no significant association of sleep duration with %BF was found.Children who slept less than 9.0 h per night had a higher risk for overweight and obesity（OR=1.29,95% CI：1.01,1.64） and abdominal obesity（OR=1.38,95% CI：1.04,1.83） as compared with those who slept for 10.0-10.9 h.Conclusions Short sleep duration is associated with obesity.It is important to ensure adequate sleep duration of children and foster their healthy lifestyle at an early stage of life.

Report on Childhood Obesity in China (9): Sugar-sweetened Beverages Consumption and Obesity

Objective To explore the associations between sugar-sweetened beverage （SSB） consumption and obesity as well as obesity-related cardiometabolic disorders among children in China. Methods A total of 6974 （boys 3558, girls 3412） children aged 6-13 years participated in the study. Each participant’s height, weight, waist circumference, fasting glucose, triglycerides, total cholesterol, high- density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured. The type of beverage consumption was determined using a self-administered questionnaire. Results SSBs were consumed regularly by 46.1% of the children. The prevalence [adjusted odds ratio （95% confidence internal （CI）] of obesity was 7.6% [as the reference group （ref.）], 10.1% [1.36（1.07, 1.74）], and 11.6% [1.46（1.21, 1.75）], among children who regularly drank milk, other beverages and SSBs, respectively. Regularly drinking SSBs elevated the likelihood of abdominal obesity [adjusted odds ratio （95% CI）： 1.36 （1.17, 1.59）]. The prevalence [adjusted odds ratio （95% CI）] of obesity among children who regularly drank sports/caloric beverages, carbonated beverages, sweet tea, and plant protein beverages was 16.8% [2.00（1.31, 3.07）], 12.7% [1.52（1.23, 1.88）], 11.5% [1.52（1.18, 1.95）], and 10.4% [1.41（1.03, 1.94）], respectively, which was higher than that of regular milk drinkers [7.6 % （ref.）]. The prevalence [adjusted odds ratio （95% CI）] of abdominal obesity among children who regularly drank sweet tea, fruit/vegetable juices, and carbonated beverages was 17.7% [1.55（1.26, 1.90）], 16.2% [1.36（1.09, 1.70）], and 15.3% [1.24（1.03, 1.50）], respectively, which was much higher than that of regular milk drinkers [12.8% （ref.）]. Conclusions Regular SSB consumption was positively related to obesity and abdominal obesity. This relationship should be investigated further using a longitudinal study design.

Dairy Consumption and Associations with Nutritional Status of Chinese Children and Adolescents

Objective This study aimed to describe frequency and quantity of total dairy consumption of Chinese children and adolescents and explore the associations between dairy consumption and nutrition status, including stunting, wasting, overweight, and obesity. Methods Participants included 28,250 children and adolescents aged 6-17 years old. A food frequency questionnaire(FFQ) including 100 kinds of food was used to collect information about frequency and quantity of dairy consumption. Determination of stunting was with a height cutoff value for age and gender, and determination for wasting, overweight, and obesity was with BMI for age and gender. Results Of the total sample, 36.1% of children aged 6-17 reported consuming dairy food more than once per day(≥ 1/day). The average total dairy intake of all the participants was 126.7 g/day. For boys, dairy consumption had an inverse correlation with stunting and wasting after controlling for confounders. For girls, dairy consumption was negatively associated with stunting and obesity after controlling for confounders as above. Conclusion Dairy consumption in Chinese children and adolescents was relatively lower than that in developed countries, and was negatively associated with stunting and wasting for boys and with stunting and obesity for girls.