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.

Macronutrients modified dietary intervention in the management of overweight/obese children and adolescents: a systematic review

The prevalence of obesity in adults and children is rapidly increasing worldwide. Obesity is among the main causes of chronic diseases and various problems, including economic consequences and they can also be affected by genetic, environmental, psychological, and socioeconomic factors. Dietary modification is a well-known and important factor in weight control, in particular, dietary macronutrient composition, food selection, dietary patterns, and energy restriction can affect weight reduction. Therefore, this systematic review aims to provide basic evidence for identifying the optimal macronutrient composition for managing obesity in Korean children and adolescents. We searched literature through an international database, studies were selected using our eligibility criteria and quality was assessed via a risk of bias tool. In our results, several studies have demonstrated that dietary macronutrient modifications affect body composition and metabolic markers in children and adolescents. In contrast, hypocaloric diets, regardless of macronutrient composition, are reportedly effective for weight loss in obese children. However, these findings were based on intervention studies that examined the association between dietary macronutrient composition and obesity in non-Korean children and adolescents. Therefore, in the future, more intervention studies are needed to elucidate this relationship and evidence between macronutrients and obesity in Korean children and adolescents.

The Role of Uncontrolled Eating and Screen Time in the Link of Attention Deficit Hyperactivity Disorder with Weight in Late Childhood

OBJECTIVE

The aim of this study was to examine the mediating roles of uncontrolled eating and sedentary behaviours in the link of attention deficit hyperactivity disorder (ADHD) and weight.

METHODS

A total of 352 children in fifth and sixth grade participated in the present study by completing the self-rated Three-Factor Eating Questionnaire and Children of Alcoholics Screening Test during regular classes. An additional questionnaire completed by their parents provided information about the children's ADHD and emotional symptoms, sedentary behaviour based on screen time, and parental variables. The questionnaires were surveyed within one week after their schools' annual physical check-up.

RESULTS

Hierarchical regression analyses revealed that uncontrolled eating was complete mediator in association between ADHD symptoms and body mass index (BMI) for boys, incomplete mediator for girls. However, screen time had no significant effect on the ADHD symptoms-BMI link for both gender.

CONCLUSION

The findings of this study suggest that gender specific intervention programs may be need to help eating behaviour in children with ADHD and overweight.

Eating habits, physical activity, nutrition knowledge, and self-efficacy by obesity status in upper-grade elementary school students

BACKGROUND/OBJECTIVES

Childhood obesity has increased in recent decades in Korea. This study was designed to examine differences in the eating habits, physical activity (PA), nutrition knowledge, and self-efficacy of children by obesity status.

SUBJECTS/METHODS

Subjects were 5th-grade children from 70 elementary schools in 17 cities nationwide. Two-stage stratified cluster sampling was employed. Survey questionnaire included items related to general characteristics, eating habits, PA, nutrition knowledge and self-efficacy. Excluding incomplete responses, 3,531 data were analyzed using SPSS. Subjects were categorized into overweight·obesity (OW) and normal weight (NW) groups based on body mass index percentiles for age by sex.

RESULTS

A total of 21.5% of subjects was overweight or obese. There were significant differences in gender, perceived stress, perception of body shape, body satisfaction, and interest in weight control between the OW and NW groups (P < 0.001). With respect to eating habits, the OW group ate breakfast (P < 0.05) and snacks (P < 0.01) less frequently, ate bigger meals (P < 0.001), and demonstrated less desirable behaviors during meals (P <0.05 in boys) compared to the NW group. The OW group participated in less PA than the NW group, especially boys. OW boys spent less time walking during weekdays (P < 0.05) or the weekend (P < 0.001), spent more time being sedentary during weekdays or the weekend (P < 0.001), and exercised a fewer number of days (P < 0.01). For girls, the OW group spent more time being sedentary during the weekend (P < 0.01) and exercised a fewer number of days by walking or bicycle riding (P < 0.05) than the NW group. Nutrition knowledge was not significantly different between the OW and NW groups. Self-efficacy (P < 0.01 in boys), especially PA self-efficacy (P < 0.01), was significantly lower in the OW than NW group.

CONCLUSIONS

This study revealed differences in eating habits, PA, and self-efficacy between OW and NW children. Obesity management programs for children need to focus on increasing self-efficacy, modifying eating habits, and increasing PA.

Increased prevalence of metabolic syndrome among hypertensive population: ten years' trend of the Korean National Health and Nutrition Examination Survey

PURPOSE

The implication of metabolic syndrome (MetS) in the hypertensive population has not been known. The prevalence and the risk factors of MetS among the hypertensive population were investigated.

METHOD

The first to the fourth Korean National Health and Nutrition Examination Survey (KNHANES) held from 1998 to 2008, nationally representative cross-sectional survey, were analyzed. MetS was defined following NCEP-ATP III guideline.

RESULTS

In the general population, MetS prevalence was about 27%, however, it was doubled in the hypertensive population, reaching almost 60%. This trend was consistent through the first to the fourth KNHANES. Moreover, although the prevalence of hypertension as well as MetS among the general population has been slightly decreasing, MetS prevalence among the hypertensive population continues to rise which is more obvious among younger patients than the general population both in men and in women. In a multivariate analysis, high BMI, menopause, smoking and daily alcohol intake were suggested as independent risk factors of MetS in hypertensive population. Finally, the presence of MetS was associated with increased prevalence of target organ damage, such as stroke, coronary artery disease and chronic renal disease.

CONCLUSION

MetS prevalence among hypertensives was much higher than expected. Moreover, MetS increased target organ damage in hypertensives. Investigation of metabolic status when initiating hypertension control could help establish more effective overall risk control.