This study aimed to investigate the associations between social jetlag (SJL), dietary behavior, physical activity, and weight status in Chinese youth. Data were derived from a cross-sectional survey in Wuhan, China in 2019. Information on SJL, the frequency of food and beverage consumption, physical activity, and BMI category were collected via a self-reported questionnaire. The Kruskal-Wallis test and ANOVA were conducted to determine differences in daily consumption frequency of food and beverage groups, BMI category, and physical activity among SJL groups. Logistic regressions and restricted cubic splines were performed to test the association between SJL and the incidence of overweight or obesity. A final sample of 3567 Chinese adolescents [mean (SD) age, 14.67 (1.72) years; 47.41% (1691) female] were included. Our findings demonstrated that adolescents with SJL may consume more unhealthy foods and fewer beneficial foods, while engaging in less moderate to vigorous physical activity (MVPA) and reporting higher BMIs. In addition, adolescents who experience more than 2 h of SJL had significant greater risk of overweight or obesity. Our findings on SJL of Chinese adolescents confirm the harmful effects of SJL and also provide insights into the etiology of obesity in Chinese adolescents.

BackgroundThe reported associations between body mass index (BMI), waist circumference (WC), and cognitive decline are not consistent, especially in older adults.ObjectiveThis study aims to investigate the longitudinal associations of BMI, WC, and their change values with cognitive decline among Chinese adults aged 60 years and older and to examine the potential moderating effect of sex on these relationships.MethodsThe participants in this study were from waves one to four (2011–2018) of the China Health and Retirement Longitudinal Study (CHARLS). Cognition function, BMI, and WC were measured at four examinations over 7 years. The interview-based cognitive assessments of memory, orientation and attention, and visuospatial ability were recorded. Standardized global cognitive scores were generated. BMI and WC were objectively measured. Mixed-effects models were performed to evaluate the associations.ResultsA final sample of 3,035 Chinese older adults [mean (SD) age, 66.94 (5.43) years; 40.16% (n = 1,219) women] were included. Higher BMI (estimate = 0.0107; SE = 0.0024; p < 0.0001) and WC (estimate = 0.0019; SE = 0.0006; p = 0.0037) were associated with slower cognition score decline over a 7-year follow-up, while greater BMI variability (estimate = −0.0365; SE = 0.0116; p = 0.0017) was related to faster cognition score decline. The results were not modified by sex. BMI-defined overweight (estimate = 0.0094; SE = 0.0043; p = 0.0298) was associated with a slower cognition score decline, and both large weight gain (estimate = −0.0266; SE = 0.0074; p = 0.0003) and large WC loss (estimate = −0.0668; SE = 0.0329; p = 0.0426) were associated with faster cognition score decline.ConclusionAmong Chinese older adults, higher BMI, higher WC, and overweight are related to slower cognitive decline, while greater BMI variability, large weight gain, and large WC loss are associated with faster cognitive decline.

To examine the association of body mass index (BMI) and a plant-based diet (PBD) with cognitive impairment in older adults, this cohort study used data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS), a national, community-based, longitudinal, prospective study in China. Cognitive function was evaluated via the Mini-Mental State Examination (MMSE). Diet was assessed using a simplified food frequency questionnaire (FFQ), and PBD patterns were estimated using the overall plant-based diet index (PDI), the healthful plant-based diet index (hPDI), and the unhealthful plant-based diet index (uPDI). BMI was measured objectively during the physical examination. Cox proportional hazard models and restricted cubic spline analyses were used. A total of 4792 participants with normal cognition at baseline were included, and 1077 participants were identified as having developed cognitive impairment during the 24,156 person-years of follow-up. A reverse J-shaped association was observed between BMI and cognitive impairment (p = 0.005 for nonlinearity). Participants who were overweight (HR = 0.79; 95% CI 0.66–0.95) and obese (HR = 0.72; 95% CI 0.54–0.96) had a decreased risk of cognitive impairment, while those who were underweight (HR = 1.42; 95% CI 1.21–1.66) had an increased risk. Lower PDI, lower hPDI, and higher uPDI were associated with an increased risk of cognitive impairment (HR = 1.32; 95% CI 1.16–1.50 for PDI; HR = 1.46; 95% CI 1.29–1.66 for hPDI; HR = 1.21; 95% CI 1.06–1.38 for uPDI). The protective effect of being overweight on cognitive impairment was more pronounced among participants with a higher PDI (HR = 0.74; 95% CI 0.57–0.95) than those with a lower PDI (HR = 0.87; 95% CI 0.67–1.12), among participants with a higher hPDI (HR = 0.73; 95% CI 0.57–0.94) than those with a lower hPDI (HR = 0.93; 95% CI 0.72–1.10), and among participants with a lower uPDI (HR = 0.61; 95% CI 0.46–0.80) than those with a higher uPDI (HR = 1.01; 95% CI 0.80–1.27). Our results support the positive associations of overweight status, obesity, an overall PBD, and a healthful PBD with cognitive function in older adults. A lower adherence to an overall PBD, a healthful PBD, and a higher adherence to an unhealthful PBD may attenuate the protective effect of being overweight on cognitive function.

This study aimed to evaluate the relationship between psychosocial variables (peer support, parental support, autonomous motivation, and controlled motivation), availability of physical activity resources in a neighborhood environment, and out-of-school moderate to vigorous physical activity (MVPA) among Chinese adolescents. The questionnaire of Family Life, Activity, Sun, Health, and Eating (FLASHE) Study was used to collect information on demographics, socioeconomic status, psychosocial variables, available physical activity resources in the neighborhood environment, and minutes of out-of-school MVPA. ANOVA analysis and multiple regression analysis were performed. The mean age of the 3833 adolescents included in our analysis was 14.7 years old (SD = 1.7). Peer support (b = 9.35, 95% CI: 7.55–11.15), autonomous motivation (b = 6.46, 95% CI: 4.09–8.82), parental support (b = 3.90, 95% CI: 1.75–6.07), and availability of physical activity resources in neighborhood environment (b = 3.18, 95% CI: 1.99–4.36) were significantly associated with out-of-school MVPA (p < 0.05). Controlled motivation was insignificantly related to minutes of out-of-school MVPA. Boys spent more time on out-of-school MVPA than girls (p < 0.001) and had a high level of peer support, parental support, and motivation (p < 0.05). Our findings suggest that interventions targeting the out-of-school MVPA among Chinese adolescents should focus on the psychosocial variables and neighborhood environment.

This study aimed to use path analysis to determine the association between perceived parental attitudes toward restricting junk food (JF)/sugar-sweetened beverage (SSB) intake and JF/SSB consumption among Chinese adolescents, and whether JF/SSB availability in the home environment and autonomous motivation of adolescents mediated the association. A cross-sectional survey was conducted using questionnaires adapted from the Family Life, Activity, Sun, Health, and Eating (FLASHE) Study to collect data on 3819 participants with an average age of 14.7 years (SD = 1.7). Spearman correlations and path analysis were performed. It was found that perceived parental attitudes were not directly associated with adolescents’ JF/SSB consumption frequency, but indirectly related to them through JF/SSB availability in the home environment and autonomous motivation of adolescents. When parents held a less positive attitude toward JF/SSB consumption and kept less JFs/SSBs at home, youth displayed more autonomous motivation for restricting JF/SSB intake and consumed fewer JFs/SSBs.