Effects of Meal Consumption on Isotonic Lingual Endurance in Healthy Adults: A Multi-Institutional Study

This study investigated the impact of meal consumption on isotonic lingual endurance in a cohort of adults across the age span without dysphagia (swallowing impairment).

Participants at three academic centres completed pre- and post-meal lingual pressure tasks. Isotonic lingual endurance was assessed using the Iowa Oral Performance Instrument (IOPI) at 50% of maximum lingual pressure (P_max) Participants consumed a standardised meal (bagel with peanut butter, carrots, and chocolate milk) between assessments. Mixed-model MANOVAs evaluated endurance changes across meal condition, age and sex.

A total of 141 adults (18-35 years, n = 75; ≥ 65 years, n = 66) completed the study. Multivariate or univariate within-subject effects of meal consumption were observed for isotonic lingual endurance across time, age, sex, or their interactions (all p > 0.65; η²p ≤ 0.004). Older adults demonstrated significantly greater isotonic lingual endurance than younger adults (p = 0.04), but sex differences did not reach statistical significance (p = 0.094). Maximum lingual pressure declined significantly with age among females but not males (p = 0.002). Longer mealtimes were observed in older adults, particularly older females, and tongue strength correlated negatively with mealtime duration (r = -0.22, p = 0.01).

Contrary to expectations, meal consumption did not reduce isotonic lingual endurance. Instead, older adults exhibited greater endurance than younger adults, potentially reflecting age-related muscle fibre adaptations or attentional differences. Findings highlight the complexity of measuring lingual endurance and provide normative reference data that may inform future swallowing assessments and dysphagia research.