Relationship between chewing features and body mass index in young adolescents

Background: Behavioural aspects of chewing may influence food intake, nutritional status and in turn body weight. Objectives: The current study aimed to study chewing features in adolescents as they naturally occur in home-based settings, and to test for a possible association with weight status. Methods: Forty-two adolescents (15.3 ± 1.3 years) were recruited (21 with healthy-weight/21 with overweight). Using a smartphone-assisted wearable electromyographic device, the chewing features of each participant were assessed over one evening, including the evening meal, in their natural home setting. Results: The mean (±SD) for chewing pace was 1.53 ± 0.22 Hz, chewing power 30.1% ± 4.8%, number of chewing episodes 63.1 ± 36.7 and chewing time 11.0 ± 7.7 minutes. The chewing pace of the group with overweight was slower than that of healthy weight (−0.20 Hz; 95% CI, −0.06 to −0.33; P =.005) while their chewing time was shorter (−4.9 minutes; 95% CI, 0.2-9.7; P =.044). A significant negative correlation was observed between BMI z-score and chewing pace (R = −.41; P =.007), and between BMI z-score and chewing time (R = −0.32; P =.039). Conclusion: The current study suggests that adolescents who are overweight eat at a slower pace for a shorter period of time than their counterparts who are a healthy weight. This unexpected finding based on objective data appears to conflict with existing questionnaire findings but provides impetus for further work testing the effectiveness of changing eating behaviour as a weight-management intervention in youth.