Eating Fast and Body Mass Index in Young Adolescents. Is there a relationship?

Abstract

Behavioural aspects of chewing may influence food intake, nutritional status, and, in turn body weight. Obesity is highly prevalent among New Zealand adolescents, it is also a concern globally, as it impacts negatively on children’s health. The aims of the current study were: 1) To study the chewing features in a group of adolescents, as they naturally occur in home-based settings 2) To test for a possible association between chewing features and body weight Forty-two participants (20 females and 22 males) aged 15.3 ± 1.3 year were recruited for this study. Based on a Z-score for Body Mass Index (BMI), half of the study participants (n = 21) were classified as being in a healthy weight range, while the other half were considered overweight-to-obese. Using a smartphone-assisted wearable electromyographic (EMG) device and a wearable camera, the participants’ chewing features were assessed for one evening, including the evening meal, in their homes. The outcome variables included chewing pace, chewing duration, and the number and power (intensity) of chewing strokes. Eating episodes could be accurately detected by both the EMG device and the wearable camera, with accuracy values ranging from 0.8 to 0.92. The EMG device, however, was more sensitive and could identify chewing episodes not detected by the camera. The chewing features (mean ± SD), as evaluated by EMG, showed a chewing pace of 1.53 ± 0.22 Hz, a chewing time of 11.0 ± 7.7 minutes and a frequency of chewing episodes of 63.1 ± 36.7 per evening (from + 5:00 pm until bedtime). The mean chewing power was 30.1 ± 4.8 %. There was a negative correlation between BMI and chewing pace (R= -0.42; P < 0.001) and between the BMI and chewing time (R = -0.32; P = 0.026). The results of the current study indicate that overweight-to-obese adolescents tend to eat in a shorter time and at a slower pace than their healthy weight counterparts.