Chewing in adolescents with overweight and obesity: An exploratory study with behavioral approach

Abstract

Physiological and behavioral aspects of masticatory function may have an impact on nutritional status, which has been little studied. The aim was to perform a comprehensive evaluation of objective, subjective and behavioral aspects of masticatory function in 231 adolescents, aged 14–17 years and compare these parameters between normal-weight (n = 115) and adolescents with overweight/obesity (n = 116). Objective aspects were examined by the Oro-facial Myofunctional Evaluation-expanded protocol (OMES-e), determining the masticatory type, chewing time/frequency, abnormal movements, and other; masticatory performance (color changeable chewing gum) and bite force were also explored. The subjective and behavioral evaluations were assessed using the Quality of Mastication Function Questionnaire, which explores the masticatory behavior and frequency/intensity of difficulty in chewing different types of foods. Results were submitted to normality tests, Chi-square, unpaired t-test and Mann-Whitney. A multiple linear regression model was used to evaluate which of the variables under study contributed to the variation in Percent Body Fat (α = 0.05). The results showed that OMES-e total score differed significantly between groups, that is, individuals with overweight showed more changes in oro-facial myofunctional aspects than normal-weight ones. Unilateral mastication was more frequent among females with overweight/obesity. They also showed greater difficulty on Habits and Fruit domains, reporting the need of adding sauce to the meal to facilitate swallowing and peeling and cutting fruit (apples) in small pieces in order to better chew them. OMES-e total score also showed a significant relationship with Percent Body Fat. Masticatory performance evaluated by chewing gum and bite force did not differ between groups. This study showed that adolescents with excess weight presented changes in masticatory behavior and greater difficulty in performing the masticatory function comparing to normal-weight ones.

Introduction

The rise in excess weight has been recently shown to occur among adolescents, reaching epidemic proportions in Western industrialized (Speiser et al., 2005) and developing countries (Misra & Khurana, 2008). Adolescence is a period of changes in physical, psychosocial, educational, and vocational domains, with an increase in behaviors considered to be risky or harmful (Moffit, 1993). The increase in the prevalence of obesity places a significant burden on their quality of life and calls for implementation of multidisciplinary treatment strategies (Doll et al., 2000, Speiser et al., 2005).

Mastication is the first step of the digestion and is responsible for the breakdown of food into smaller particles suitable for gastrointestinal absorption of nutrients (Pedersen, Bardow, Jensen, & Nauntofte, 2002). Obesity has been associated with increased consumption of highly processed foods (Brennan, Sweeney, Liu, & Mantzoros, 2010), which have greater palatability, more calories and less consistency (Bes-Rastrollo et al., 2008, Drewnowski and Specter, 2004). According to Bellisle, Guy-Grand, and Le Magnen (2000), the consumption of such foods speeds the digestion process, decreases the chewing time and the number of masticatory cycles. Comminution of food has also shown to influence gastric emptying rates (Pera et al., 2002) and previous studies suggested a relationship between eating fast and excess weight (Otsuka et al., 2006).

Due to its complexity, the masticatory function can be evaluated by different aspects; the measure of masticatory performance and efficiency may reflect the quality of mastication by determining the number of chews necessary to render food ready for swallowing (Pedersen et al., 2002). Muscle (bite) force and the number of functional tooth units are determinants of masticatory performance, which suggests that their maintenance may be of importance for promoting healthful functional status of the masticatory system (Hatch, Shinkai, Sakai, Rugh, & Paunovich, 2000). Chewing can also be evaluated subjectively, using questionnaires in which the individual's chewing behavior and difficulties while performing the function are assessed (Hilasaca-Mamani et al., 2015, Hilasaca-Mamani et al., 2016). Masticatory efficiency and masticatory behavior are aspects that may not be directly related; hence, both indexes should be evaluated with sufficient consideration of their differences (Sato & Yoshiike, 2010). Using a validated questionnaire, it is possible to assess if the subject avoids certain kind of food because of its size or consistency or if the individual cuts food into small pieces and/or eats food together with beverages to facilitate chewing and swallowing.

Excess weight may be associated to alterations in some aspects of mastication (Kibayashi, 2011), but the relation between masticatory behavior and obesity remains to be determined. Thus, the aim of the present study was to perform a comprehensive evaluation of masticatory function and behavior in adolescents with different body weights, including objective and subjective aspects, in a cross-sectional study.