Physical Activity and Sedentary Screen Time in Obese and Overweight Children Living in Different Environments

Physical activity in infancy and early childhood: a narrative review of interventions for prevention of obesity and associated health outcomes

In the context of the childhood obesity epidemic, this narrative review aims to explore opportunities to promote physical activity (PA) between birth and age 5 years as well as the health outcomes associated with PA in early childhood. Although early childhood is an ideal time to promote healthy habits, guidelines for PA have often ignored early childhood given the limited evidence for children <5 years old. Herein we discuss and highlight infant, toddler and preschool age interventions to promote PA and prevent obesity both in the short and long-term. We describe novel and modified interventions to promote improved early childhood health outcomes, encompassing cardiorespiratory, muscle, and bone strengthening components necessary for short-term motor development and long-term health. We call for new research aimed at developing and testing innovative early childhood interventions that may be performed in home or childcare settings, monitored by parents or caregivers.

Joint association of screen time and physical activity with anthropometric measures in Iranian children and adolescents: the weight disorders survey of the CASPIAN-IV study

BACKGROUND

This study aims to assess the joint association of screen time (ST) and physical activity (PA) with anthropometric indices among Iranian children and adolescents.

METHODS

In this national study, 23,183 school students, aged 6-18 years, were studied. By using a multi-stage cluster sampling method, they were selected from rural and urban areas of 30 provinces of Iran. ST and PA were assessed by self-administered validated questionnaires. Height, weight, hip and waist circumferences (WC) were measured according to standard protocols, and body mass index (BMI) was calculated. ST of <2 h per day was categorized as "low" and ≥2 h per day as "high". PA levels were obtained by a 7-day recall of sports or activities that made participants sweat or make their legs feel tired, or games that made them breathe heavily. Using this questionnaire, the score of 1-1.9 was categorized as "low" and scores between 2 and 5 as "high" PA. Logistic regression analyses were used to evaluate the joint association of PA and ST categories with odds of anthropometric measures.

RESULTS

In both genders, those students categorized as "Low PA & High ST" had the highest levels of BMI z-scores (boys: 0.15±1.12, girls: 0.17±1.08), WC (boys: 69.93±13.89 cm, girls: 67.30±11.26 cm), and hip circumference (boys: 82.41±13.90 cm, girls: 84.05±13.7 cm), as well as the highest prevalence of overweight (boys: 15.32%, girls: 14.04%) (p<0.001 in all comparisons). In linear multivariate model, students with "High PA & High ST" had significant increased levels of z-scores for BMI, WC and hip circumference (p<0.05).

CONCLUSIONS

The current findings underscore the importance of reducing ST along with increasing PA for prevention and control of excess weight in children and adolescents.

Associations among Screen Time and Unhealthy Behaviors, Academic Performance, and Well-Being in Chinese Adolescents

Screen time is negatively associated with markers of health in western youth, but very little is known about these relationships in Chinese youth. Middle-school and high-school students (n = 2625) in Wuhan, China, completed questionnaires assessing demographics, health behaviors, and self-perceptions in spring/summer 2016. Linear and logistic regression analyses were conducted to determine whether, after adjustment for covariates, screen time was associated with body mass index (BMI), eating behaviors, average nightly hours of sleep, physical activity (PA), academic performance, and psychological states. Watching television on school days was negatively associated with academic performance, PA, anxiety, and life satisfaction. Television viewing on non-school days was positively associated with sleep duration. Playing electronic games was positively associated with snacking at night and less frequently eating breakfast, and negatively associated with sleep duration and self-esteem. Receiving electronic news and study materials on non-school days was negatively associated with PA, but on school days, was positively associated with anxiety. Using social networking sites was negatively associated with academic performance, but positively associated with BMI z-score, PA and anxiety. Screen time in adolescents is associated with unhealthy behaviors and undesirable psychological states that can contribute to poor quality of life.