Intertwined relationship of dietary patterns and circadian clock

Circadian rhythms orchestrate daily fluctuations in feeding behavior, hormonal activity, and metabolic function through coordinated interactions between the central clock and peripheral oscillators. Dietary patterns, defined by both macronutrient composition and the timing of food intake, function as potent cues that reshape these rhythms. This narrative review summarizes experimental evidence describing how diet influences circadian organization and how circadian disruption alters metabolic outcomes primarily in murine models. Genetic disruption of core clock components such as CLOCK, BMAL1, CRY, or PER abolishes feeding rhythmicity and desynchronizes metabolic pathways, resulting in obesity, impaired glucose regulation, and hepatic lipid accumulation. Dietary composition also influences circadian organization, as high-fat, ketogenic, or modified-protein diets shift the phase or amplitude of peripheral clock gene rhythms and alter metabolic outputs across tissues. Feeding-time misalignment produces substantial phase shifts in hepatic and adipose oscillations and aggravates diet-induced metabolic dysfunction. In contrast, restricting food intake to consistent daily windows restores rhythmic metabolic states in the liver, adipose tissue, and intestine and improves systemic homeostasis even without reducing caloric intake. Together, these findings show that both macronutrient composition and feeding-time alignment influence the phase and synchrony of peripheral circadian rhythms and the metabolic processes governed by these rhythms. Understanding these relationships provides mechanistic insight into diet–circadian interactions and supports the development of circadian-aligned dietary strategies aimed at promoting metabolic stability.