Chronotype is associated with eating behaviors, physical activity and overweight in school-aged children.

BACKGROUND: A later chronotype has been found to be associated with unhealthy habits and diseases, such as an unhealthy diet and metabolic syndrome in adults. Little is known about the association between chronotype, eating habits, physical activity and obesity. Thus, this study aimed to explore the relationships between chronotype, eating behaviors, physical activity, and overweight in Chinese school-aged children. METHODS: Data from this study was based on 952 schoolchildren (10-12 y) from six primary schools that participated in China. Anthropometric measurements of height and body weight were performed. Information about sleeping habits, dietary behaviors, and other lifestyle behaviors was gathered using a self-administered questionnaire. Multiple linear regression analysis or multivariable logistic regression model was performed to assess the associations between chronotype, eating behaviors, physical activity, and overweight. RESULTS: Nearly 70% (69.9%) of the participants had a self-reported morning chronotype. Multiple linear regression analysis revealed chronotype score was positively associated with physical activities (all P values < 0.001) and sleep duration (all P values < 0.001) and negatively associated with BMI, meal time, eating jet lag and social jet lag (all P values < 0.001). Multivariable logistic regression analysis showed that compared to morning types, non-morning types individuals were more likely to be overweight (OR = 1.593, P value < 0.05), and had more frequent consumption of fast food (OR = 1.616, P value < 0.05), but less frequent consumption of milk (OR = 0.716, P value < 0.05), less time taking part in moderate (OR = 1.356, P value < 0.05) or muscle strengthening (OR = 1.393, 1.877, P value < 0.05) physical activity. CONCLUSIONS: This study indicates that early chronotype children are more active, have healthier dietary habits, get more sleep, have shorter social jet lag, and are less likely to be overweight than non-early chronotype children. Our findings suggest that later chronotype may be a potential indicator in the early detection of overweight, unhealthy eating, and physical inactivity behaviors. Chronotype has been found to have an important impact on individual's health. In the present study, we conducted a cross-sectional study to investigate the association between chronotype, eating behaviors, physical activity, and overweight in school-aged children. The findings showed that children with early chronotype is associated with more active, healthier dietary behaviors, longer sleep duration, short social jet lag, and a lower risk of overweight.

Effect of changes in body mass index and waist-to-height ratio on blood pressure in 11- to 13-year-old children: a prospective population study.

BACKGROUND: Existing evidence about associations between change in body mass index (BMI) and waist-to-height ratio (WHtR) change and high blood pressure are relatively limited. AIMS: We aimed to investigate the associations of general overweight (based on BMI) and abdominal obesity (based on WHtR) change with high blood pressure in Chinese children. SUBJECTS AND METHODS: A school-based cohort study in Ningbo region (China) was conducted among children with baseline evaluations in October 2016 with follow-up two years later. A total of 1432 children aged 11-13 years participated in this study. RESULTS: Our results showed that a change from normal BMI or WHtR to overweight or abdominal obesity in children was associated with high blood pressure (adjusted odds ratio (AOR), 2.62; p<0.05 or AOR, 2.79; p<0.05, respectively). In addition, an increased risk of high blood pressure was observed in children who maintained overweight or abdominal obesity (AOR, 1.67; p<0.05 or AOR, 1.69; p<0.05, respectively), but not in children who experienced remission to non-excess weight. Interestingly, children who increased BMI or WHtR had greater impact on SBP than on DBP. CONCLUSION: The 2-year longitudinal study indicated that general overweight or abdominal obesity can predict the risk factor of high blood pressure in children. However, children who remitted to non-excess weight did not exhibit an increased risk of high blood pressure.

Self-reported eating speed is associated with overweight among Chinese schoolchildren: a cross-sectional survey.

PURPOSE: This study aimed to examine the association between eating speed and overweight in Chinese schoolchildren. METHODS: In all, 664 schoolchildren (10-12 years) from three primary schools participated in this study in China. Their height and body weight were measured. Information about eating speed and other lifestyle behaviors were collected using a self-administered questionnaire. Multivariable logistic regression model was used to estimate the odds ratio (OR) and 95% confidence interval (95% CI) for overweight. RESULTS: Data from 629 students were analyzed. 26.2% of participants reported they were eating fast. The prevalence of overweight (including obesity) was 22.9%, and the mean of sleep duration was 9.69 (SD = 0.63) hours (Table 1). In the multiple linear regression analysis, slower eating speed was independently associated with lower BMI (B = - 0.70, 95% CI - 1.26 to - 0.14) and TG (B = - 0.16, 95% CI - 0.28 to - 0.04). In addition, participants who ate fast were more likely to be overweight (OR 1.81, 95% CI 1.19-2.75) after adjusting for potential confounding factors. CONCLUSIONS: This study indicates that eating fast is associated with overweight among Chinese school children. LEVEL OF EVIDENCE: Cross-section descriptive study, Level V.

Association between alcohol consumption and metabolic syndrome among Chinese adults.

OBJECTIVE: To assess the prevalence of metabolic syndrome (MetS) in Chinese adults living in Ningbo and to examine the association between alcohol consumption and MetS and its medical components. DESIGN: A representative survey in Ningbo was conducted in 2015 covering socio-demography. A FFQ together with additional questionnaires was used to collect information on alcohol consumption, diet, demography, lifestyle and medical information. Multivariable logistic regression and generalised linear models were used to examine the association between alcohol consumption and both MetS and its medical components, respectively. SETTING: Ningbo, China. PARTICIPANTS: A total of 2853 adults ≥ 20 years (44 % men) in this final analysis. RESULTS: The prevalence of frequent alcohol drinkers and MetS was 29·9 % and 28·0 %, respectively. Significantly higher prevalence of MetS and mean values of medical components were found in the group of frequent alcohol drinkers with an exception for HDL-cholesterol, compared with less or non-alcohol drinkers. Frequent alcohol consumption was associated with higher odds of developing MetS and positively associated with medical components excepting waist circumference. CONCLUSIONS: Frequent alcohol consumption contributed to a higher prevalence of MetS and unfavourable influence on MetS and its medical components among Chinese adults. A public health intervention on alcohol restriction is necessary for the prevention and control of the ongoing epidemic MetS.

Dinner-to-bed time is independently associated with overweight/obesity in Chinese school-aged children.

PURPOSE: Little is known about the association between dinner-to-bed time and obesity. Thus, this study was aimed to assess the relationships between dinner-to-bed and overweight/obesity in Chinese school-aged children in Ningbo, China. METHODS: Data of this study were based on 1667 schoolchildren (14-15 years) from 14 primary schools participated in this study in China. Anthropometric measurement of height, body weight and waist circumference (WC) was performed. Information about meal duration and other lifestyle behaviors was collected using a self-administered questionnaire. Multivariable logistic regression model was performed to assess the association between dinner-to-bed time and overweight/obesity. Restricted cubic spline regression was drawn to evaluate the shape of the relation between dinner-bed-time and the odds of overweight. RESULTS: Among the study participants, the prevalence of overweight was 17.6%, and the mean of dinner-to-bed time was 4.26 (0.93) h. In the logistic regression analysis, participants who had dinner-to-bed time less than 3 h or 3.01 ~ ≦ 4.00 h are more likely to be overweight (OR = 1.94, 95% CI 1.10-3.42; OR = 1.65, 95% CI 1.03-2.65, respectively) or characterised by abdominal obesity (OR = 3.03, 95% CI 1.86-4.95; OR = 2.61, 95% CI 1.73-3.92, respectively) compared with dinner-to-bed time more than 5 h. In addition, long dinner-to-bed time was associated with lower risks of overweight (OR = 0.83, 95% CI 0.70-0.97) and abdominal obesity (OR = 0.63, 95% CI 0.54-0.73). The cubic spline regression analysis showed that the association between dinner-to-bed time and overweight/abdominal obesity seems to be a linear. CONCLUSIONS: This study indicates that short dinner-to-bed time is associated with an increased likelihood of being overweight or characterised by abdominal obesity among Chinese school-aged children. LEVEL OF EVIDENCE: Level V; cross-section descriptive study.

Sleep duration and overweight in Chinese adolescents: a prospective longitudinal study with 2-year follow-up.

PURPOSE: This prospectively designed study aimed to investigate the association between sleep duration and overweight in a cohort of Chinese adolescents. METHODS: A school-based cohort study with a 2-year follow-up was conducted among Chinese adolescents in Ningbo region (China). For the baseline study, 1901 school-aged Chinese children aged 12-13 years were recruited. Finally, 1510 adolescents were successfully reinterviewed in October 2018. Participants were asked to complete a self-administered questionnaire, and their heights and weights were directly measured. RESULTS: Overweight adolescents had shorter sleep duration or later bedtimes than non-overweight children in baseline (P < 0.05). In the multivariable linear regression analysis, sleep duration was marginally significantly correlated with body mass index (BMI) at baseline and significantly correlated with this parameter at a 2-year follow-up (ß = - 0.23, 95% confidence interval (CI): - 0.51 to 0.04, P < 0.1; ß = - 0.27, 95% CI: - 0.42 to - 0.11, P < 0.05, respectively). After adjusting for potential confounders, the multivariable logistic regression analysis revealed associations of a longer sleep duration at baseline with a reduced likelihood of participants being overweight both at baseline and at follow-up (adjusted odds ratio (AOR) = 0.81, 95% CI: 0.66 to 1.00, P = 0.05; AOR = 0.43, 95% CI:0.24 to 0.76, P < 0.05, respectively). CONCLUSIONS: Shorter sleep was associated with an increased likelihood of being overweight in Chinese adolescents, while a 1-h decrease in sleep per night led to a more than 50% increase in the overweight risk at the 2-year follow-up.

Insufficient Sleep Duration and Overweight/Obesity among Adolescents in a Chinese Population.

OBJECTIVES: The objective of this study was to investigate the relationship between sleep duration and overweight/obesity among Chinese adolescents. METHODS: A school-based cross-sectional study was conducted among Chinese adolescents in 2016. In total, 2795 school-aged Chinese children aged 12 to 13 years participated in this study. Participants were asked to complete self-administered surveys during a 45-min class period in their classroom. Details of the questionnaire about health-related behaviors included sleep habits, physical activity, screen time, cigarette use, and alcohol use. Height, weight, waist circumference and hip circumference were directly measured. RESULTS: The mean sleep duration was 8.7 h/day. In total, 43.0% of the participants had a sleep duration of less than 9 h/day. Sleep duration was significantly inversely related to BMI, waist circumference, hip circumference and WHtR in multiple linear regression analyses in both genders. Logistic regression models showed that insufficient sleep (<9 h/day) was associated with high odds of overweight/obesity among both young boys and girls. CONCLUSIONS: Insufficient sleep duration was associated with overweight/obesity in Chinese adolescents, and short sleep duration was probably associated with central adiposity, especially among boys.

25-Hydroxyvitamin D Status and Its Association with Sleep Duration in Chinese Schoolchildren.

OBJECTIVE: To examine the association between 25-Hydroxyvitamin D (25(OH)D) levels and sleep duration among Chinese adolescents. SUBJECTS AND METHODS: A school-based cross-sectional study was conducted among Chinese adolescents in 2017. Data on a total of 800 adolescents aged 8⁻14 years was used for this study. Anthropometric measurements such as height and weight were measured by trained research staff. Serum 25(OH)D and lipids were measured in the laboratory. Sleep habits and other health-related behaviors were tested by questionnaire. RESULTS: 25(OH)D levels were significantly positively correlated with sleep duration (r = 0.11, p < 0.05). In multivariate logistic regression analyses, insufficiency/deficiency of vitamin D (25(OH)D ≤ 20 ng/mL) was significantly associated with increased probability of short sleep (AOR = 1.67, 95% CI = 1.14⁻2.43). CONCLUSIONS: Low 25(OH)D levels were independently associated with the risk of insufficient sleep in Chinese adolescents.

Associations between sleep duration and physical activity and dietary behaviors in Chinese adolescents: results from the Youth Behavioral Risk Factor Surveys of 2015.

OBJECTIVE: To assess the association between sleep duration and physical activity and dietary behaviors among adolescents in a representative sample. METHODS: The analysis was performed using data from the 2015 Ningbo Youth Risk Behavior Survey. Associations between physical activity and dietary behaviors and sleep duration were examined on weighted data using logistic regression. RESULTS: Of the 10726 students, roughly 40% reported sleep duration <8 h. Longer sleep duration was associated with higher likelihood of milk intake, fruit consumption, vegetable consumption, water consumption, moderate physical activity, and muscle-strengthening physical activity, and with a lower likelihood of cigarette use, alcohol use, sweets intake, Western fast food intake, and breakfast skipping. CONCLUSION: Insufficient sleep may be common among Chinese adolescents. Sleep duration was associated with dietary behaviors, physical activity, and other health-related behaviors. These findings suggest that sleep duration could be a potential target for many health-risk behaviors in young adolescents.

Lifestyle interventions for adults with impaired glucose tolerance: a systematic review and meta-analysis of the effects on glycemic control.

OBJECTIVE: Previous meta-analyses have demonstrated that lifestyle modification can reduce the blood glucose levels in patients with type 2 diabetes, although the effects of changes in the blood glucose level on impaired glucose tolerance (IGT) remain controversial. This review therefore aimed to determine the efficacy of lifestyle interventions in adults with IGT. METHODS: We searched the Medline, Cochrane Library, EMBASE and Science Citation Index databases and reference lists of the included articles. Two independent reviewers extracted the data and assessed the quality of the included studies; a total of nine randomized controlled trials met the inclusion criteria. In addition, we tested for trial heterogeneity and calculated the pooled effects size using the random effects model. RESULTS: The overall interventions were associated with a decline in the 2-hour plasma glucose levels [standardized mean differences (SMD) -0.56; 95% confidence interval (CI), -1.01 to -0.10; I(2), 96.6%]. Moreover, dietary intervention (SMD -0.53; 95% CI -0.77 to -0.28) and physical intervention (SMD -0.42; 95% CI -0.63 to -0.20) were each associated with a decline in the 2-hour plasma glucose levels compared with that observed in the control participants. The overall interventions were associated with a decline in the fasting plasma glucose (FPG) levels (SMD -0.27; 95% CI -0.38 to -0.15; I(2) = 47.1%). In addition, physical intervention (SMD -0.25; 95% CI -0.44 to -0.05) and combined dietary and physical intervention were each associated with a decreased FPG level (SMD -0.28; 95% CI -0.44 to -0.12) compared with that observed in the control participants. CONCLUSION: Lifestyle modification based on physical or dietary interventions or both is associated with improvements in the 2-hour plasma glucose and FPG levels in IGT patients.