Association of nighttime fasting duration, breakfast time and dinner time with healthy aging in Chinese older adults: a cross‑sectional study

Proper eating/fasting cycle can regulate circadian rhythms, thereby influencing metabolic regulation, oxidative stress, and cognitive function. However, its association with overall health remains understudied. This study aimed to explore the relationship between nighttime fasting duration (NFD), breakfast time, dinner time and healthy aging among Chinese older adults. A cross-sectional study was conducted between September 2021 and December 2023, involving 947 older adults aged 60 years and above from various socioeconomic regions in China. Data on NFD and meal timing were obtained through a validated dietary behavior questionnaire. Healthy aging was defined as free of major chronic diseases, no limitation in physical function, no cognitive impairment, and no depressive symptoms. Logistic regression models were used to analyze the relationship between the NFD, breakfast time and dinner time, and healthy aging. A total of 901 participants were included, with a median age of 69.00 years (IQR: 64.50, 74.00) and 56.60% being female. Of these, 29.86% met the criteria for healthy aging. An inverted U-shaped relationship was observed between NFD and healthy aging (P nonlinear = 0.001). Compared to participants with 13 h ≤ NFD<14 h, those with NFD<12 h, 14 h ≤ NFD<15 h, and NFD≥15 h had lower odds of healthy aging, with adjusted ORs of 0.46 (95% CI: 0.23, 0.93), 0.62 (95% CI: 0.41, 0.95), and 0.34 (95% CI: 0.15, 0.77), respectively. A similar inverted U-shaped association was found for both breakfast time (P nonlinear = 0.028) and dinner time (P nonlinear = 0.007). Compared with participants who had breakfast 6:00–7:00, those who had breakfast before 6:00 or after 7:00 had lower odds of healthy aging, with adjusted ORs of 0.68 (95% CI: 0.47, 0.98), 0.78 (95% CI: 0.44, 1.40), respectively. Compared with participants who had dinner 17:00–18:00, those who had dinner before 17:00 or after 18:00 had lower odds of healthy aging, with adjusted ORs of 0.48 (95% CI: 0.23, 1.00), 0.49 (95% CI: 0.29, 0.82), respectively. Optimal circadian-related eating patterns, specifically a nighttime fasting duration of 13h to < 14 h, breakfast between 6:00 and 7:00, and dinner between 17:00 and 18:00, were associated with the highest odds of healthy aging among Chinese older adults.