Chewing habits and masticatory performance are associated with obesity in 9-to 10-year-old children: A cross-sectional study from the Osaka MELON Study

Objectives: This study aimed to examine the relationships of masticatory performance and chewing habits with obesity in Japanese elementary school children. Methods: The participants were 1,403 children aged 9-10 years in Osaka City. Chewing habits were assessed via questionnaires, and masticatory performance was measured using a color-changeable chewing gum. Obesity was determined by the percentage of overweight based on height and weight. Multivariate logistic regression analyses were conducted to calculate odds ratios for obesity, using chewing habits and masticatory performance as explanatory variables, adjusted for sex, DMFT index, and Hellman dental developmental stage. Results: Logistic regression analysis showed significant associations between obesity and sex, eating fast, and lower masticatory performance in all participants (OR=1.54, 1.73, 1.50; 95 %CI=1.08-2.17, 1.23-2.44, 1.05-2.15, respectively). In boys, eating fast, eating with mouth full, and lower masticatory performance were significantly associated with obesity (OR=1.84, 1.59, 1.63; 95 %CI=1.16-2.92, 1.03-2.46, 1.02-2.59, respectively). No variable was significantly associated in girls. When eating fast and lower masticatory performance were combined, it was significantly associated with obesity, with the strongest odds ratio observed in boys exhibiting both behaviors (OR=3.00, 95 %CI=1.49-6.07). Conclusions: In 9- to 10-year-old children, eating fast, eating with mouth full, and lower masticatory performance were linked to obesity, particularly in boys. Furthermore, the association with obesity was higher when eating fast and lower masticatory performance were combined. Clinical significance: To prevent obesity in schoolchildren, approaching the problem not only from the habitual aspect of eating fast, but also from the functional aspect of lower masticatory performance is necessary.