Lifestyles, obesity and psychosocial health in children and adolescents

Abstract

Background: Psychosocial well-being in youth remains a growing public health concern. Lifestyles and obesity are important factors. Evidence from non-Western settings, especially with a different cultural background and more recent social-historical development, may shed light on the disparities in lifestyles and psychosocial indicators and the associations of modifiable factors with psychosocial health.

Objectives: This thesis aimed to examine the secular trends in screen use and self-rated health and the prospective associations of modifiable factors, including breakfast habits, screen use, and changing weight status with psychosocial health in children and adolescents in Hong Kong.

Methods: I obtained the large population-based and territory-wide data of students participating in the annual health assessment scheme from 1999/2000 to 2014/2015 in Hong Kong. Age and sex-standardized prevalence of TV viewing, video game playing, and very poor/poor and good/excellent self-rated health were estimated. The disparities over time were examined using Generalized estimating equations (GEE). The associations of breakfast habits, TV viewing and video game playing with emotional and behavioral problems were estimated using GEE with a logit link. The trajectories of weight status during 6-11 years were estimated using growth mixture modeling, and their associations with low self-esteem were assessed using multivariable logistic regression.

Results: From 1999/2000 to 2008/09, the age and sex-standardized prevalence of ≥2 h/d TV viewing decreased and that of ≥1 h/d video game playing increased; both screen use were more prevalent in children from lower socioeconomic families. From 1999/2000 to 2014/15, the prevalence of very poor/poor self-rated health increased and that of good/excellent self-rated health decreased. Adolescents being obese or having unhealthy lifestyles had higher risks of poorer self-rated health. Compared with eating breakfast at home, eating breakfast away from home predicts total emotional and behavioral problems and some syndromes (adjusted odds ratios 1.22-2.04). Skipping breakfast showed stronger associations with more syndromes (1.34-2.29). The associations of breakfast habits were stronger in younger age with total and attention problems (P<0.03) and in lower weight status with delinquent behaviors (P=0.005). Compared with daily TV viewing for 1- <2 hours, viewing for ≥4 hours predicted total emotional/behavioral symptoms and some syndromes (adjusted odds ratio 1.21-1.62). Compared with occasionally playing video game, never playing predicted anxiety/depression (1.44) and thought problems (1.36), and playing for ≥1 hour predicted thought problems, delinquent and aggressive behaviors (1.41-1.42). From Primary 1 to 6, four distinct weight status trajectories were identified: underweight/normal (76.8%), increasing (8.1%), decreasing (4.2%) and chronic overweight/obesity (10.9%). Late-onset or chronic overweight/obese showed lower self-esteem (1.20-1.43) except for the parent/home-related self-esteem, while those being decreasingly overweight /obese showed no significant difference (P=0.53).

Conclusions: Children in lower socioeconomic families had increased risks of screen engagement. Adolescents in Hong Kong had worsening self-rated health, especially for those being obese and having unhealthy lifestyles. The associations of eating breakfast away from home, skipping breakfast and none or excess screen engagement with psychosocial problems were negative despite being weak. Late-onset or chronic overweight/obesity predicted low general, social and academic/school-related self-esteem. Obese children were vulnerable to lower self-esteem in non-domestic environments.