Impact of masticatory behaviors measured with wearable device on metabolic syndrome (Preprint)

BACKGROUND It has been widely recognized that the mastication behaviors are related to the health of the whole body such as lifestyle-related disease. However, many studies were based on subjective questionnaire, or were limited to small-scale research in the laboratory due to the lack of device for measuring mastication behaviors of daily meal objectively. Recently, a small wearable masticatory counter device, called bitescan, for measuring masticatory behavior was developed. This wearable device is designed to assess objective masticatory behavior just by putting on the ear in not only laboratory but also in usual situations. OBJECTIVE This study aimed to compare mastication behaviors in the laboratory with that in daily meals and to clarify the relation between mastication behaviors measured by wearable device and metabolic syndrome (MetS). METHODS Ninety-nine healthy volunteers (50 men and 49 women, 36.4 ± 11.7y) participated in this study. The mastication behaviors i.e. number chews and bite, number of chews per bite, chewing rate were measured using the wearable ear-hung type device. Mastication behaviors during eating a rice ball (100 g) in the laboratory and during usual meals for an entire day were monitored, and the daily energy intake was calculated. Participants’ abdominal circumference, fasting glucose concentration, blood pressure, and serum lipids were also measured. The mastication behaviors in laboratory and in meals for one entire day was compared. The participants were divided into two groups using Japanese criteria for MetS (positive / negative for MetS or each MetS components), and mastication behaviors was compared. RESULTS Mastication behaviors in the laboratory and during daily meals were significantly correlated (number of chews r=.360; P<.001, number of bites r=.493; P<.001, number of chews per bite r=.334; P=.001, chewing rate r=.512; P<.001). Although a positive correlation was observed between the number of chews during the 1-day meals and energy intake (r=.262, P=.009), the number of chews per calorie ingested was negatively correlated with energy intake (r=-.315, P=.002). Eight participants were diagnosed with MetS and 12 with pre-MetS. The number of chews and bites for a rice ball in pre-MetS (+) group was significantly lower than the pre-MetS (-) group (P=.016, P=.027, respectively). Additionally, these scores for the positive abdominal circumference, and blood pressure subgroup were also less than the counterpart groups (P=.006, P=.010 for chews, P=.006, P=.016 for bites, respectively). The number of chews and bites for an entire day in the hypertension subgroup were significantly lower than in the other groups (P=.020, P=.006). Furthermore, the positive abdominal circumference and hypertension subgroups showed lower number of chews per calorie ingested, for 1-day meals (P=.049, P=.021, respectively). CONCLUSIONS These results suggested that masticatory behaviors do not change with environmental, and that masticatory behaviors might have relation to MetS and MetS components. CLINICALTRIAL A protocol containing all methods and materials was uploaded to the Individual Case Data Repository of University Hospital Medical Information Network, prior to the start of data collection (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034453).