Characterizing Puree Bite Sizes in People with Normal and Disordered Swallowing: Predictors and Impact on Swallowing Safety and Efficiency during Flexible Endoscopic Evaluation of Swallowing

Introduction: Pureed foods are an important part of standardized swallowing assessments, yet there is limited research characterizing typical bite sizes of pureed foods in people with normal and disordered swallowing, nor how puree bite sizes relate to functional swallowing outcomes. Therefore, this study aimed to characterize self-selected bite sizes of pureed foods in outpatient adults by: (1) assessing the effects of puree type, puree color, swallowing instruction, transnasal endoscopy, and flexible endoscopic evaluation of swallowing (FEES) on puree bite size; and (2) examining the relationships between puree bite size, patient demographics, and level of swallowing impairment. As a secondary aim, we assessed the relationships between puree bite size, pharyngeal residue, penetration, and aspiration.

Forty-nine outpatient adults undergoing FEES were prospectively enrolled. Patients completed randomized trials of applesauce and pudding with/without clinician-added food coloring, with/without a single-swallow swallowing instruction, and with/without FEES. Bite sizes were measured by weighing cups of puree before and after spoonfuls of puree were taken by patients. Multilevel regressions were used to assess the effects of puree type, puree color, swallowing instruction, transnasal endoscopy, FEES, demographics, and level of swallowing impairment on puree bite size. Multilevel regressions were also used to examine relationships between bite size, pharyngeal residue, penetration, and aspiration.

Across all self-selected puree bites (n = 343), the median bite size was 10.3-11.1 mL. Clinician-added food coloring, transnasal endoscopy, and FEES reduced bite sizes by 8-22%. Self-selected puree bite sizes were not predicted by patient demographics or level of swallowing impairments. However, larger bites of pureed foods were associated with greater amounts of oropharyngeal and hypopharyngeal residue. The relationship was more pronounced for people with severe-to-profound swallowing impairment.

Median self-selected puree bite sizes for adults with and without dysphagia is 10-11 mL, with larger bites associated with more pharyngeal residue. Additionally, FEES appears to result in a significant reduction in typical bite sizes, limiting the ability to test natural self-selected sizes of puree food during FEES. Therefore, to better approximate real-world eating during FEES, clinicians should consider testing puree volumes of ∼10 mL as part of a standardized protocol.