Temporal Dietary Patterns and Frailty in Korean Older Adults: Evening-Skewed and Morning-Evening Eating Patterns...

Meal timing has emerged as a potential determinant of healthy aging; however, evidence linking temporal dietary patterns (TDPs) with frailty remains limited. We aimed to identify distinct TDPs among older adults and examine their associations with frailty and its components.

In this cross-sectional study, 4184 adults aged ≥ 65 years from the Korea National Health and Nutrition Examination Survey (2016-2018) were analyzed. Temporal energy-intake trajectories from 24 h recalls were clustered using dynamic time warping-based kernel k-means. Frailty was defined using a modified Fried phenotype, and diet quality was assessed employing the Healthy Eating Index. Survey-weighted logistic regression and mediation analyses were performed.

Five distinct patterns were identified as follows: balanced (n = 1665, 38.8%), steady (n = 735, 17.8%), midday (n = 737, 18.0%), evening (n = 627, 15.2%), and morning-evening (n = 420, 10.2%). Among these, the evening-skewed (characterized by a disproportionate concentration of energy intake in the late evening; adjusted odds ratio [OR] = 1.48, 95% confidence interval [CI] = 1.03-2.10) and morning-evening (characterized by higher energy intake in both the morning and evening; OR = 1.43, 95% CI = 1.01-2.03) patterns were associated with higher frailty risk than the balanced pattern. Mediation analysis showed that higher total energy intake had a protective role in the evening-skewed pattern; however, this benefit was offset by the adverse impact of late-night eating, resulting in increased frailty risk. In the morning-evening pattern, both a direct association with frailty and an indirect pathway mediated by lower energy intake and poorer diet quality contributed to the increased frailty risk.

Older adults with evening-skewed or morning-evening TDPs had greater frailty risk than those with balanced eating patterns. Optimizing meal timing-by reducing late-day energy loading and ensuring adequate overall intake and dietary quality-may represent a feasible chrono-nutrition strategy for frailty prevention.