Differential roles of oral physiology and oral processing behaviors on eating rate and snack intake in adults with...

Oral physiology and oral processing behaviors influence bolus formation and potentially eating rate. However, the role of oral physiology on intake among adults with a healthy dentition remains unclear. Here, we examined associations between physiological measures (salivary flow rate and masticatory performance), oral processing behaviors (bolus formation and eating rate), and pretzel intake. In a single laboratory session, adults (n = 68, 66% women) completed assessments of salivary flow rate (parafilm), masticatory performance (gum mixing task), and bolus formation (mini-pretzels). Bolus formation was evaluated with and without metronome guided chewing, and expectorated boluses were assessed for cohesiveness. Eating rate (g/min) was quantified from video recordings during consumption of pretzels (70 g) and a fixed portion of 30 g carrots. Pretzel intake was measured as the difference between pre and post consumption weights of the pretzel portion. Self-reported eating rate was measured on a 101-point scale (0 to 100, anchored with Extremely Slow and Extremely Fast). Higher salivary flow rate associated with a more cohesive bolus, while masticatory performance showed a marginal association with carrot eating rate but not with pretzel eating rate, bolus cohesiveness, or pretzel intake. Self-reported eating rate was significantly associated with measured eating rate for both carrots and pretzels, but not with pretzel intake. For pretzels, larger bite sizes and faster eating rate were both associated with greater pretzel intake, with men exhibiting larger bite sizes, faster eating, and greater consumption than women. Collectively, these data confirm that eating rate and bite size influence pretzel intake, while also showing minimal evidence that the physiological measures used here directly influence eating rate or pretzel intake.