Effects of textured foods on masticatory muscle activity in older adults with oral hypofunction.

BACKGROUND: Preserving sufficient oral function and maintaining proper nutrition are essential to prevent frailty. Thus, we have developed "munchy" foods that contain harder textures and are rich in protein. OBJECTIVES: This study aimed to test the effects of masticating textured foods on masticatory muscle activity in young and older adults. METHODS: Twenty young and 32 community-dwelling older individuals participated in this study. After measuring oral function, we subdivided the older participants into normal and oral hypofunction (OHF) groups. Two test foods (meatloaf and chicken ball) were prepared to have a harder texture using specific ingredients (munchy) or not (control). The participants ate 10 g of the test foods in random order while being measured for masseter muscle activity with a surface electromyogram (EMG). We calculated the number of chewing cycles and integrated muscle activity of the masseter muscle from the EMG data and tested for differences by food texture or age group. RESULTS: The number of chewing cycles, mean EMG amplitude and integrated EMG activity was significantly higher for the munchy foods than for the controls for all groups. The integrated masseter muscle EMG activity was significantly increased in the normal older group than in the young group for both food types, but not significantly different between in OHF and young groups. CONCLUSIONS: Our findings suggest that eating textured foods will lead to increased masticatory load and therefore increased muscle activity, especially in older adults. Application of textured food may change dietary habits in older adults.