Lifestyle Risk Factors and the Population Attributable Fractions for Overweight and Obesity in Chinese Students of Zhejiang Province

Abstract

Objectives: To assess the relationship between modifiable lifestyle factors and risk of overweight/obesity in Chinese students, and to evaluate the predicting prevalence of overweight if the lifestyle risk factors were removed. Methods: A cross-sectional survey was conducted among 40,141 students in grade three and above (8-24yrs) in 2019 in Zhejiang Province, China. Physical examination was performed, and a self-administered questionnaire was used to collect lifestyle information, including dietary behavior, physical activity, TV watching, sleeping, smoking, drinking, and tooth-brushing habits. Logistic regression models were performed to assess the relationship between overweight/obesity and a series of lifestyle factors. Population attributable fractions (PAFs) were used to calculate the predicting prevalence of overweight/obesity if lifestyle risk factors were removed. Results: The prevalence of overweight/obesity of participants was 25.5% (male 32.3%, female 18.1%). Overweight/obesity were associated with adverse lifestyle factors, such as watch TV ≥1 h/day (OR = 1.14, 95% CI: 1.11-1.22), insufficient sleep (OR = 1.14, 95% CI: 1.11-1.22), and irregular toothbrushing habits (OR = 1.19, 95% CI: 1.01-1.39). Based on the calculated PAFs, the predicted prevalence of overweight/obesity would decline moderately if lifestyle factors were modified, with the magnitudes of decrease vary by sex, age and residence. Generally, a larger reduction was estimated if the sleeping time was increased and TV time was reduced, with the prevalence of overweight/obesity decreased by 1.1% (95% CI: 0.7, 1.5%) and 0.9% (95% CI: 0.6, 1.2%), respectively. Conclusions: Predicted prevalence of overweight/ obesity in Chinese students may decrease if modifiable lifestyle risk factors were removed. The attributable risk for obesity of lifestyle behaviors varied in age, sex and residence groups. The findings of this study may provide insights for planning and optimizing future obesity intervention endeavors.

Keywords: Zhejiang province; lifestyle factors; obesity; population attributable fraction; student.

Figure 1

Adjusted population attributable fractions of lifestyle factors for overweight/obesity. Models were adjusted for age, sex, city, urban/rural area and all other factors. Dots were the estimated values. Error bars were 95% confidence intervals. (B, C) exercise wasn't shown because it was insignificant and had too wide CI to be shown. (D) toothbrushing habit wasn't shown because it was insignificant and the number of people who occasionally or didn't brush their teeth every day was small (54/11205). (E, F) fired food and exercise weren't shown because they were insignificant and had too wide CI to be shown.

Figure 2

Predicting prevalence of overweight/obesity if the risk factor was removed, ranked by the magnitude of rate deduction. Models were adjusted for age, sex, city, urban/rural area and all other factors. Dots were the estimated values. Error bars were 95% confidence intervals. (B, C) exercise wasn't shown because it was insignificant and had too wide CI to be shown. (D) toothbrushing habit wasn't shown because it was insignificant and the number of people who occasionally or didn't brush their teeth every day was small (54/11205). (E, F) fired food and exercise weren't shown because they were insignificant and had too wide CI to be shown.