Chrononutrition and Aging: The Link between Circadian Biology and Dietary Strategies for Healthy Longevity

Abstract

Background: Chrono-nutrition examines how meal timing interacts with circadian rhythms, endogenous 24-hour cycles that regulate physiology. Aging naturally dampens these rhythms (phase shifts and reduced amplitude), disturbing metabolism and increasing disease susceptibility.

Methods: This study is a narrative review. Relevant articles were identified through searches in the electronic databases PubMed, Scopus, and Google Scholar using the keywords ("Chrononutrition" OR "Circadian rhythm" OR "Meal timing" OR "Time- restricted feeding") AND ("Aging" OR "Elderly" OR "Healthy longevity") AND ("Metabolism" OR "Microbiome"). Articles published in English and Persian up to 2025 were reviewed. Inclusion criteria included human and animal studies, original articles, and reviews related to chrononutrition and aging. Exclusion criteria included articles without full text and those unrelated to the main topic. Additional sources were obtained by manually searching the reference lists of the selected articles.

Results: It reveals a bidirectional relationship between diet and circadian function in aging. Advancing age naturally causes phase shifts and amplitude reductions in circadian oscillations, disturbing metabolism and increasing susceptibility to chronic diseases. Critically, however, dietary practices, particularly consistent feeding-fasting cycles, can actively strengthen circadian rhythms even without altering diet composition, thereby improving metabolic coordination and potentially mitigating age-related pathologies. Conversely, the frequent polypharmacy seen in the elderly can disrupt circadian regulation, exacerbating nutrient deficiencies. Aging also induces substantial changes in the gut microbiome, which closely communicates with the host circadian system and influences inflammatory, metabolic, and immune responses. Moreover, individual chronotypes contribute to varying metabolic responses to meal timing among older adults, necessitating personalized approaches.

Conclusion: The conclusion emphasizes that chrono-nutrition serves as a pivotal regulator of metabolic health, longevity, and the attenuation of functional decline with age. Strategically aligning eating schedules with internal biological clocks offers a novel and effective public health intervention to reduce risks associated with modern lifestyles. When integrated with healthy dietary choices, consistent physical activity, and proper sleep patterns, chrono-nutrition can form a cornerstone of successful aging. The review provides actionable dietary insights for older populations while clearly identifying current research gaps (such as the interplay between polypharmacy, microbiome shifts, and chronotypes) to guide future investigations