The Relationship between Chewing Habits and Obesity by Grade Level among Elementary and Junior High School Students

Abstract

Objective: To examine the relationship between chewing habits and obesity in elementary and junior high school students by grade level.

Methods: We used the data from a survey on food and nutrition education for elementary and junior high school students conducted by the Education Committee in Minato Ward, Tokyo in January 2018. After examining physique and chewing habits by sex and grade using a χ² test, we classified subjects into two groups (slimming tendency and standard weight or obesity tendency) and examined the relationships between obesity and chewing habits by sex using a χ² test and logistic regression analysis.

Results: A total of 8,704 students were analyzed (analysis target rate, 95.0%). Logistic regression analysis showed that children with poor chewing habits were more obese than children who had good chewing habits, even after adjusting for factors such as grade, physical activity, breakfast frequency, late-night meals, bedtime, and smartphone usage time [un-adjusted model 1: Odds ratio (95% confidence interval) for boys = 2.17 (1.69~2.78) and girls = 2.06 (1.34~3.20); grade-only adjusted model 2: boys = 2.14 (1.67~2.75) and girls = 2.04 (1.32~3.16); all-factor adjusted model 3: boys = 1.94 (1.50~2.52) and girls = 1.89 (1.20~2.98)].

Conclusions: Poor chewing habits may be associated with obesity in elementary and junior high school students irrespective of sex even after adjusting for grade and lifestyle.