Association between sedentary behavior, screen time and metabolic syndrome among Chinese children and adolescents.

BACKGROUND: The aim of the study was to investigate the relationship between sedentary behavior, screen time and MetS among Chinese children and adolescents aged 7-17 years. Data was obtained from the China National Nutrition and Health Surveillance of Children and Lactating Mothers in 2016-2017. METHODS: Data on sedentary time, screen time, and MetS indicators were obtained through physical and health questionnaires, anthropometric measurements, and clinical examinations. MetS was defined according to the Cook's criteria. Wilcoxon rank sum test and chi-square test were applied for comparisons of measurement data and counting data, respectively. The relationship between sedentary time, screen time, and MetS and its components was analyzed using a multivariate logistic regression model. RESULTS: The prevalence of MetS among 7-17-year-old students in 2016-2017 was 5.45%. Compared to those with low sedentary behavior, in high sedentary behavior groups, the prevalence of abdominal obesity, high TG, low HDL-C, and MetS was high in boys, and the prevalence of abdominal obesity, high TG, hyperglycemia, and MetS was high in girls. Moreover, for those who reported ≥ 3 h/day of screen time, the prevalence of abdominal obesity, low HDL-C, and MetS was higher in boys, and the prevalence of abdominal obesity and MetS was higher in girls. After adjusting for confounding variables, the risks of abdominal obesity, high TG, low HDL-C, and MetS were higher in high-level sedentary time group, and the risks of abdominal obesity and MetS were 1.15 and 1.14 times higher for those who spent ≥ 3 h/day on screen time, respectively. CONCLUSIONS: This study shows that high levels of sedentary time and screen time were associated with an increased likelihood of MetS among Chinese children and adolescents aged 7-17 years. Reducing sedentary behavior and screen time may contribute to the prevention of metabolic diseases.

[Prevalence and trends of low body weight among elderly population aged 60 years and above in China in 2002-2015].

OBJECTIVE: Understand the current situation and changing trends of low body weight in elderly population aged 60 years and above. METHODS: Data was collected from 2002 Chinese Nutrition and Health Survey, 2010-2013 Chinese Nutrition and Health Surveillance and 2015 Chinese Adult Chronic Disease and Nutrition Surveillance. Multi-stage stratified cluster random sampling was used for all surveys or surveillance. In 2002, 27 778 samples of people aged 60 and over were taken from 132 monitoring sites in mainland China. In 2010-2013, 34 581 subjects were selected from 150 monitoring points in mainland China. In 2015, 59 576 subjects were selected from 302 monitoring points in mainland China. Questionnaires collected basic information such as gender, and date of birth, and information such as height and weight were collected through physical examination. RESULTS: The prevalence of low body weight in the elderly aged 60 years and above showed a downward trend from 2002 to 2015 in China(P<0.01). The prevalence of low body weight decreased from 11.67% in 2002 to 5.19% in 2015. The prevalence of low body weight among males decreased from 11.51% in 2002 to 5.21% in 2015. The prevalence of low body weight among females decreased from 11.83% in 2002 to 5.17% in 2015. The prevalence of low body weight in the elderly aged 60 years and above showed an upward trend with age. The prevalence of low body weight in urban areas decreased from 5.85% in 2002 to 3.31% in 2015. The prevalence of low body weight in rural areas decreased from 16.25% in 2002 to 6.67% in 2015. The prevalence of low body weight in seven geographic regions of China decreased from 2002 to 2015. The prevalence of low body weight was highest in the elderly population aged 60 years and above in South China(9.49%(95%CI 8.61%-10.38%)) and lowest in North China(2.55%(95%CI 2.15%-2.95%)) in 2015. CONCLUSION: The prevalence of low body weight among the elderly aged 60 years and above in China decreased from 2002 to 2015. The prevalence of low body weight increased with age. The prevalence was higher in rural areas than in urban areas, and the prevalence in South China was higher than in other geographic regions.

[Comparison study of food, energy and nutrient intake by 24-hour dietary recall method on two consecutive days versus three consecutive days].

OBJECTIVE: To compare the differences in estimated food, energy, and nutrient intakes between the consecutive 3 days 24-hour dietary recall(24HR)(referred to as the 3-day method) and consecutive 2 days 24HR(referred to as the 2-day method) to provide a basis for the use of consecutive 2 days 24HR in China nutrition surveillance. METHODS: Using objective sampling to select participants in northern and southern provinces, dietary data were obtained through consecutive 3 days 24HR, and the average intakes of food, energy and nutrients were calculated for three days from Thursday to Saturday and two days on Friday and Saturday, respectively. The 3-day method was considered as the reference standard method to evaluate the performance of the 2-day method for estimating food, energy and nutrient intakes. RESULTS: Among 778 participants aged 18-60 years in urban and rural areas of two provinces, the errors of the mean and median of 2-day method for estimating the intake of four major food categories less than 6% compared with the 3-day method, and there were significant equivalencies(P<0.025) and no significant differences in four major food categories group(P>0.05). Of the 24 food groups estimated by the 2-day method, 17 had mean errors within 5%, the largest error was in animal offal(13.45%) and the smallest in fruit(0.15%), and there were significant equivalencies(P<0.025) and no significant differences in seven food groups(P>0.05). For energy and nutrients, the mean and median errors of energy were less than 0.5% and there were significant equivalencies(P<0.025) and no significant differences for energy(P>0.05). Among the 25 nutrients, except sodium, iodine and vitamin E, the mean and median errors of the other 22 nutrients were less than 5%, and there were significant equivalencies(P<0.025) and no significant differences in 16 nutrients(P>0.05). CONCLUSION: There was little difference between the two survey method in assessing the intake of high consumption frequency foods, energy and most nutrients at group level, the 2-day method can be used as an alternative to the 3-day method to collect dietary intake data with high consumption rates in the population.

The Relationship between Birth Weight and the Risk of Overweight and Obesity among Chinese Children and Adolescents Aged 7-17 Years.

Obesity is a major public health issue in children and adolescents. Our study aimed to examine the impacts of birth weight on overweight and obesity among Chinese children and adolescents. Using data from the China National Nutrition and Health Surveillance of Children and Lactating Mothers in 2016-2017, we included 10,041 participants aged 7-17 years. According to birth weight, participants were categorized into six groups, and the birth weight category of 3000 to 3499 g was chosen as the reference group, containing the largest number of children. Logistic regression analyses were used to investigate the association of birth weight with the risk of being obese at 7 to 17 years of age in multivariable-adjusted models. A restricted cubic spline was utilized to show the odds ratios (ORs) of obesity at different birth weight levels. The adjusted ORs for overweight were 0.98 (95%CI 0.63, 1.53), 1.02 (95%CI 0.84, 1.25), 1.34 (95%CI 1.16, 1.55), 1.72 (95%CI 1.35, 2.18), and 1.17 (95%CI 0.71, 1.96) in several birth weight groups, compared with group C (3000-3499 g). The adjusted ORs for obesity were 0.82 (95%CI 0.48, 1.40), 0.77 (95%CI 0.60, 0.98), 1.33 (95%CI 1.13, 1.57), 1.97 (95%CI 1.53, 2.53), and 2.01 (95%CI 1.27, 3.19). Furthermore, children in the post-pubertal stage had a slightly higher risk of overweight and obesity than those in the pre-pubertal and pubertal stage. Moreover, these associations were stronger among boys. The lower part of normal birth weight range is associated with a lower risk of overweight and obesity in children and adolescents. However, higher levels of birth weight increase risk.

Deficiency of Energy and Nutrient and Gender Differences among Chinese Adults: China Nutrition and Health Survey (2015-2017).

Half of Chinese adults face the double burden of overweight/obesity and micronutrient deficiencies, and nearly 40% of them are severely overweight/obese or have micronutrient deficiencies. This study used the data from China Nutrition and Health Survey (CNHS) from 2015 to 2017 to estimate the prevalence of inadequate dietary micronutrient intake (including vitamin A, vitamin B1, vitamin B2, vitamin C, cCalcium, iron and sodium) in Chinese adults and further determine the differences in micronutrient intake by gender, age and BMI. A total of 61,768 subjects were included in this study, of which 33,262 (54%) were female. The intake of energy and all macronutrients decreased with age, and the intake was higher in men than in women. Inadequate energy intake occurs in adults of all ages. In terms of nutrient intake, women had a higher rate of insufficient carbohydrate intake than men in all age groups. Inadequate protein intake was more common in women aged 18-49 years (60.9%) than in men. Compared with women, men had a higher rate of vitamin B2 intake. Insufficient vitamin B3 intake was more common in women aged 18-49 years (35.6%), men aged 65-79 years (39.7%) and men aged 80 years and above (47.9%). In all age groups, insufficient vitamin C intake is higher in women than in men-up to 85.8 percent in women aged 80 years old and above. Compared with men in the same age group, insufficient intake of calcium and iron is more obvious in women. Women have significantly higher rates of inadequate intake of calcium, iron and sodium than men. In the analysis of correlations between BMI or demographic data and micronutrient intakes, the likelihood of micronutrient intakes being insufficient was higher in the central and western regions in all age groups compared to the eastern regions. The risk of insufficient micronutrient intake was higher in obese men and women aged 18-49 years and 50-64 years. Underweight and overweight women in the 65-79 age group were more likely to have inadequate micronutrient intake. Obese women over 80 years of age were less likely to have inadequate micronutrient intake. No significant difference was found between urban and rural areas for each age group.