Chrononutrition, Dietary Patterns, and Sleep: A Narrative Review of Current Evidence and Practical Implications

Sleep and nutrition are closely interconnected through behavioral, metabolic, and circadian pathways, yet the strength of evidence varies considerably across dietary exposures. This narrative review synthesizes current evidence on nutrients, foods, dietary patterns, chrononutrition, caffeine and alcohol in relation to sleep, while also considering the effects of insufficient sleep on dietary intake and metabolic health. The relevant literature was identified through searches of PubMed/MEDLINE, Scopus, and Web of Science, supplemented by examination of reference lists and targeted searches. Higher-quality dietary patterns, particularly Mediterranean-style diets, are generally associated with more favorable sleep characteristics, although predominantly observational evidence limits causal interpretation. Intervention studies of individual foods and supplements have reported benefits for selected sleep outcomes, but findings remain heterogeneous and are often based on small samples. Evidence for meal timing and time-restricted eating is similarly inconsistent and does not support a single eating schedule for improving sleep. In contrast, caffeine and alcohol have relatively well-established sleep-disrupting effects. Insufficient sleep can also alter dietary intake, energy balance, glucose regulation, and adiposity, highlighting the bidirectional nature of these relationships. Nutritional approaches may complement broader strategies for sleep and health, but current evidence does not support specific foods, supplements, or eating schedules as stand-alone treatments for sleep problems.