It is unknown if time-restricted feeding confers a protective effect on the physical function of older adults. The aim of this study was to assess prolonged nightly fasting in association with performance-based lower-extremity function (LEF) in a large population of community-dwelling older adults. A cross-sectional study was carried out among 1226 individuals ≥64 years from the Seniors-ENRICA-II (Study on Nutrition and Cardiovascular Risk in Spain) cohort. Habitual diet was assessed through a validated diet history. Fasting time was classified into the following categories: ≤9, 10-11 and ≥12 h/d (prolonged nightly fasting). Performance-based LEF was assessed with the Short Physical Performance Battery (SPPB). After adjusting for potential confounders, a longer fasting period was associated with a higher likelihood of impaired LEF (OR for the second and third categories v. ≤ 9 h/d fasting: 2·27 (95 % CI 1·56, 3·33) and 2·70 (95 % CI 1·80, 4·04), respectively; Ptrend < 0·001). Fasting time showed a significant association with the SPPB subtests balance impairment (OR for highest v. shortest fasting time: 2.48; 95 % CI 1·51, 4·08; Ptrend = 0·001) and difficulty to rise from a chair (OR 1·47; 95 % CI 1·05, 2·06; Ptrend = 0·01). The risk associated with ≥12 h fasting among those with the lowest levels of physical activity was three times higher than among those with ≤9 h fasting with the same low level of physical activity. Prolonged nightly fasting was associated with a higher likelihood of impaired LEF, balance impairment, and difficulty to rise from a chair in older adults, especially among those with low levels of physical activity.
Keywords: Cross-sectional studies; Intermittent fasting; Older adults; Physical function; Short Physical Performance Battery; Time-restricted feeding.