[Study on the relationship between family-related factors and obesity of children and adolescents aged 6-17 years]

Analyzing Neck Circumference as a Tool for Evaluating Overweight and Obesity in Chinese Adolescents

Overweight and obesity at an early age are important criteria for predicting chronic diseases. Each anthropometric method available to assess obesity has its limitations. Recently, neck circumference (NC) has received greater attention as a new evaluation index. This study aimed to investigate the relationship between NC and overweight in Chinese Yi adolescents. A total of 647 Chinese Yi male and female students, aged 13-18 years, were randomly selected from a junior high school and a senior middle school in Leshan, Sichuan Province of China. The measurement indexes included height, weight, waist circumference (WC), and NC, and clinical information was collected by trained physicians. The neck cutoff values were determined through the receiver operating characteristic (ROC) curve and the area under the curve (AUC). The correlation among NC, body mass index (BMI), and WC was determined by Pearson's correlation coefficient. The ROC analysis revealed that the AUC values were 0.79-0.95 for boys and 0.83-0.91 for girls. The correlation among NC, BMI, and WC in obese boys and girls was higher than 0.70 in both genders. In addition, the NC cutoff values of high BMI ranged from 31.0 cm to 36.1 cm for boys and 31.2 cm to 34.5 cm for girls, respectively. There was a significant positive correlation between NC and obesity in Chinese Yi adolescents. The NC can be used as an additional index to predict the obesity of Chinese Yi adolescents.

[Mediating effect of milk intake between family socioeconomic status and body mass index of children and adolescents]

OBJECTIVE

To examine the association between family socioeconomic status (SES) and body mass index (BMI) z-score of children and adolescents, and the mediating effect of milk intake in this association.

METHODS

In the study, 2 496 students and their parents were selected from 16 schools (4 urban middle schools, 4 rural middle schools, 4 urban primary schools, and 4 rural primary schools) using a stratified cluster sampling method. The frequency and amount of weekly milk intake from the 7-day Food Records reported by the students were extracted. The parents' education and household income were the indicators of family SES. The mediating effect of milk intake between family SES and BMI z-score of children and adolescents were tested using the PROCESS add-on SPSS software.

RESULTS

Parents' education level and household income were positively correlated with BMI z-score of children and adolescents (P=0.001 and 0.038, respectively). The overall average daily intake of milk was (0.92±0.84) servings, and the frequency was (4.43±2.70) days per week. The students of primary school, in urban areas, with higher parents' education level, with higher household income, and being non-obese were likely to have higher frequency and amount of milk intake. Milk intake was one of the mediating factors in the relationship between family SES and BMI z-score of children and adolescents. Specifically, the mediating effect of the frequency of milk intake accounted for -6.57% and -10.21% of the total effects of the association between the parents' education and the household income with BMI z-score of children and adolescents, respectively. The mediating effect of the daily intake of milk accounted for -3.63% and -5.86% of the total effects of the association between the parents' education and the household income with BMI z-score of children and adolescents, respectively.

CONCLUSION

The milk intake of Chinese children and adolescents still needs to be improved. High family SES was found to contribute to high BMI z-score, mediated by the milk intake which was the protective factors of BMI z-score. Further research is needed to study other dietary or physical exercise behaviors that mediate the relationship between family SES and BMI z-score of children and adolescents in order to adopt more targeted interventions.

Dietary Patterns and Association with Obesity of Children Aged 6⁻17 Years in Medium and Small Cities in China: Findings from the CNHS 2010⁻2012

Childhood obesity is associated with both near- and longer-term health implications. Few studies have been conducted to explore the associations between dietary patterns and obesity among Chinese children and adolescents. The present study was designed to identify dietary patterns and their relationships with childhood obesity in medium and small cities. This is a cross-sectional study of children participants aged 6⁻17 years old in the 2010⁻2012 China Nutrition and Health Survey (CNHS). Socio-demographics, life-style, physical activity, anthropometric variables, and hundred-item food frequency questionnaires (FFQs) were collected. Household income was classified as low, middle, and high. Traffic tools, from non-advanced to advanced, included walking, biking, bus, and car. Dietary patterns were identified using factor analysis of data from FFQs. Two dietary patterns were identified: a Westernized pattern (i.e., high cakes, snacks, sugary beverages, aquatic products, red meat, fruits, and nuts) and a Traditional Chinese pattern (i.e., high cereals, tubers, legumes, fried cereal food, and vegetables). The Westernized pattern was positively correlated with energy intake, household income, traffic tools, and negative correlated with age and housework time. The Traditional Chinese pattern was positively correlated with age, energy intake, and housework time, and negatively correlated with household income and traffic tools. After adjusting for confounding factors, the Westernized pattern was found to be associated with BMI increment, yielding β coefficients (95% confidence interval, 95% CI) of 0.57 (0.40, 0.85) for the fourth quartile. In addition, the Westernized pattern was also found to be significantly associated with an increased risk of obesity, yielding an odds ratio (OR, 95% CI) of 1.49 (1.21, 1.84) from fully-adjusted confounders. Promoting healthier eating patterns could help to prevent obesity in Chinese children. The findings of this study could be used to guide the development of evidence-based preventive nutrition interventions to curb childhood obesity epidemic in small⁻medium cities in China.