[Value of body fat mass measured by bioelectrical impedance analysis in predicting abnormal blood pressure and abnormal glucose metabolism in children].

OBJECTIVE: To study the value of body fat mass measured by bioelectrical impedance analysis (BIA) in predicting abnormal blood pressure and abnormal glucose metabolism in children. METHODS: Stratified cluster sampling was used to select the students aged 6-16 years, and a questionnaire survey and physical examination were performed. The BIA apparatus was used to measure body fat mass. Body mass index (BMI), body fat mass index (FMI), and fat mass percentage (FMP) were calculated. Fasting blood glucose level were measured. RESULTS: A total of 14 293 children were enrolled, among whom boys accounted for 49.89%. In boys and girls, the percentile values (P60, P65, P70, P75, P80, P85, P90, P95) of FMI and FMP fitted by the LMS method were taken as the cut-off values. Based on the receiver operating characteristic curve analysis, the P70 values with a better value in predicting abnormal blood pressure and blood glucose metabolism were selected as the cut-off values for excessive body fat. When FMI or FMP was controlled below P70, the incidence of abnormal blood pressure or abnormal glucose metabolism may be decreased in 8.25%-43.24% of the children. CONCLUSIONS: The evaluation of obesity based on FMI and FMP has a certain value in screening for hypertension and hyperglycemia in children, which can be further verified in the future prevention and treatment of obesity and related chronic diseases in children.

[Study on the relations among the screen-based sedentary behaviors, family factors and body mass index of children].

OBJECTIVE: To explore the relations among screen-based sedentary behaviors (SSB), family factors and body mass index (BMI) of children, and to study how family factors have effect on BMI through influencing SSB. METHODS: A total of 1,846 students aged 7-11 years from 12 primary schools in one district of Beijing were included. Their body weight and height were measured to calculate the BMI. The time of SSB and family factors were investigated by using questionnaires. The time of SSB was the total time of watching TV and videos, playing computer games and iPad each day during the past 7 days recalled by children. The family factors included the parents' education, occupation, the parents'time of SSB, whether the parents told their child the harm of SSB, the parents'time limit for the children's SSB. The parents'education and occupation were used for calculating the family socioeconomic score. RESULTS: The median time of SSB for children was 1 hour/day, and the interquartile range was 1 hour/day. The BMI of the children with the parents' time limit for the children's SSB less than 120 min/day were smaller than the children with the parents'time limit not less than 120 min/day, in both the boys (1.63 kg/m2, P<0.001) and the girls (0.85 kg/m2, P=0.004). The family socioeconomic score, the parents'SSB time, whether the parents told their children the harm of SSB were not related to the children's BMI . The mediation effects of SSB time for children on the association between the parents'time limit for the children's SSB and BMI were -0.222 kg/m2 (95%CI:-0.432, -0.095) for boys and -0.187 kg/m2 (95%CI: -0.507, -0.049) for girls, which accounted for 13.67% of the total effects for boys and 22.11% for girls. CONCLUSION: The parents' time limit for the children's SSB has effect on their BMI through influencing their SSB time. Parents' supervision on the behaviors of children produces larger benefit for BMI than health education conveyed by parents. Therefore, parents' participation in supervising the behaviors of children are indispensable for preventing and controlling childhood obesity.

The Effect of a Multifaceted Intervention on Dietary Quality in Schoolchildren and the Mediating Effect of Dietary Quality between Intervention and Changes in Adiposity Indicators: A Cluster Randomized Controlled Trial.

Some studies have found associations between dietary quality and obesity and their concurrent changes were observed in a few interventions. The present study aimed to assess the effect of a multifaceted intervention for childhood obesity on dietary quality and examine the mediating effect of dietary quality between the intervention and changes in adiposity indicators. Based on the social ecological model, the cluster randomized controlled trial included five components (three targeted children and two targeted their environment). In total, 1176 children from three cities in China participated in a baseline (2018) and end-of-trial (2019) examination, including 605 children in the intervention group and 571 in the control group. Self-reported behavior and anthropometric measures were collected at both time points. The Diet Balance Index Revision (DBI-07) was calculated to assess dietary quality. Generalized linear mixed models were used to estimate the intervention effect on dietary quality and its mediating effects were examined. Compared to the controls, the proportion of sugar-sweetened beverage (SSB) intake (OR = 0.27, p < 0.001, corrected p < 0.001) decreased in the intervention group. Higher bound scores (HBS) of the DBI-07 indicating over-intake decreased in the intervention group compared to the controls (mean difference = −1.52, p = 0.005, corrected p = 0.015). Changes in the HBS partially mediated the associations between the intervention and changes in body mass index, waist circumference, and body fat percentage. Future intervention should promote knowledge, attitudes, and behaviors related to dietary quality.

Effectiveness of a Multifaceted Intervention for Prevention of Obesity in Primary School Children in China: A Cluster Randomized Clinical Trial.

Importance: A rapid nutritional transition has caused greater childhood obesity prevalence in many countries, but the repertoire of effective preventive interventions remains limited. Objective: To determine the effectiveness of a novel multifaceted intervention for obesity prevention in primary school children. Design, Setting, and Participants: A cluster randomized clinical trial was conducted during a single school year (from September 11, 2018, to June 30, 2019) across 3 socioeconomically distinct regions in China according to a prespecified trial protocol. Twenty-four schools were randomly allocated (1:1) to the intervention or the control group, with 1392 eligible children aged 8 to 10 years participating. Data from the intent-to-treat population were analyzed from October 1 to December 31, 2019. Interventions: A multifaceted intervention targeted both children (promoting healthy diet and physical activity) and their environment (engaging schools and families to support children's behavioral changes). The intervention was novel in its strengthening of family involvement with the assistance of a smartphone app. The control schools engaged in their usual practices. Main Outcomes and Measures: The primary outcome was the change in body mass index (BMI; calculated as weight in kilograms divided by height in square meters) from baseline to the end of the trial. Secondary outcomes included changes in adiposity outcomes (eg, BMI z score, prevalence of obesity), blood pressure, physical activity and dietary behaviors, obesity-related knowledge, and physical fitness. Generalized linear mixed models were used in the analyses. Results: Among the 1392 participants (mean [SD] age, 9.6 [0.4] years; 717 boys [51.5%]; mean [SD] BMI, 18.6 [3.7]), 1362 (97.8%) with follow-up data were included in the analyses. From baseline to the end of the trial, the mean BMI decreased in the intervention group, whereas it increased in the control group; the mean between-group difference in BMI change was -0.46 (95% CI, -0.67 to -0.25; P < .001), which showed no evidence of difference across different regions, sexes, maternal education levels, and primary caregivers (parents vs nonparents). The prevalence of obesity decreased by 27.0% of the baseline figure (a relative decrease) in the intervention group, compared with 5.6% in the control group. The intervention also improved other adiposity outcomes, dietary, sedentary, and physical activity behaviors, and obesity-related knowledge, but it did not change moderate- to vigorous-intensity physical activity, physical fitness, or blood pressure. No adverse events were observed during the intervention. Conclusions and Relevance: The multifaceted intervention effectively reduced the mean BMI and obesity prevalence in primary school children across socioeconomically distinct regions in China, suggesting its potential for national scaling. Trial Registration: ClinicalTrials.gov Identifier: NCT03665857.