Meal timing plays a crucial role in metabolic health, influenced by the interaction between the circadian clock and metabolic homeostasis. Misaligned meal timing, such as late or nighttime eating, disrupts the internal circadian clock, increasing the risk of obesity and related diseases like type 2 diabetes and cardiovascular disease. Conversely, meal timing aligned with cellular rhythms can optimize tissue and organ function. This review discusses the metabolic effects of meal timing, underlying mechanisms, and factors influencing it, including chronotype, genetics, and environmental factors. It also explores the potential of precision nutrition to align meal timing with circadian rhythms, aiding in the prevention and treatment of obesity and metabolic diseases. The circadian clock regulates physiological processes, with the suprachiasmatic nucleus (SCN) as the master clock. Peripheral clocks in tissues like the liver, gut, and adipose tissue also play a role in metabolic rhythms. Disruptions in the circadian clock, such as those seen in rodents, lead to metabolic dysfunctions like obesity, insulin resistance, and cardiovascular issues. Human studies show that mistimed food intake, especially in shift workers, is associated with increased obesity and cardiometabolic risks. Late meal timing is linked to higher body mass index (BMI), impaired glucose tolerance, and increased risk of type 2 diabetes. Factors influencing meal timing include social structures, work schedules, and cultural practices. Chronotype, determined by genetic and environmental factors, affects meal timing preferences. Late chronotypes tend to eat later, which may contribute to metabolic issues. Genetic factors also play a role in meal timing, with variations in core clock genes influencing circadian rhythms and meal timing. The microbiome and its composition are also heritable and influence meal timing and metabolic health. Time-restricted eating (TRE) is a strategy that shortens the eating window, potentially improving metabolic outcomes. Studies show that TRE can enhance glucose control, reduce insulin resistance, and lower triglyceride levels. However, results vary, and more research is needed to determine optimal TRE protocols. Meal composition and timing are interconnected, with nutrient timing affecting satiety and appetite. Chronotype influences meal timing, with late chronotypes eating later and having higher calorie intake. Lifestyle factors, such as caffeine and alcohol consumption, also affect meal timing and energy intake. Artificial light exposure and sleep-wake patterns disrupt circadian rhythms, leading to changes in meal timing and increased energy intake. Sleep deprivation can alter meal timing and food intake patterns, while longer sleep is associated with earlier dinner times and reduced sugar consumption. Geography, religion, and social status influence meal timing and dietary habits, with cultural practices affecting food intake and cardiometabolic health. Overall, understanding the complex interplay between meal timing, circadian rhythms, and metabolic health is essential for developing effective interventions to prevent and treat obesity and related diseases.Meal timing plays a crucial role in metabolic health, influenced by the interaction between the circadian clock and metabolic homeostasis. Misaligned meal timing, such as late or nighttime eating, disrupts the internal circadian clock, increasing the risk of obesity and related diseases like type 2 diabetes and cardiovascular disease. Conversely, meal timing aligned with cellular rhythms can optimize tissue and organ function. This review discusses the metabolic effects of meal timing, underlying mechanisms, and factors influencing it, including chronotype, genetics, and environmental factors. It also explores the potential of precision nutrition to align meal timing with circadian rhythms, aiding in the prevention and treatment of obesity and metabolic diseases. The circadian clock regulates physiological processes, with the suprachiasmatic nucleus (SCN) as the master clock. Peripheral clocks in tissues like the liver, gut, and adipose tissue also play a role in metabolic rhythms. Disruptions in the circadian clock, such as those seen in rodents, lead to metabolic dysfunctions like obesity, insulin resistance, and cardiovascular issues. Human studies show that mistimed food intake, especially in shift workers, is associated with increased obesity and cardiometabolic risks. Late meal timing is linked to higher body mass index (BMI), impaired glucose tolerance, and increased risk of type 2 diabetes. Factors influencing meal timing include social structures, work schedules, and cultural practices. Chronotype, determined by genetic and environmental factors, affects meal timing preferences. Late chronotypes tend to eat later, which may contribute to metabolic issues. Genetic factors also play a role in meal timing, with variations in core clock genes influencing circadian rhythms and meal timing. The microbiome and its composition are also heritable and influence meal timing and metabolic health. Time-restricted eating (TRE) is a strategy that shortens the eating window, potentially improving metabolic outcomes. Studies show that TRE can enhance glucose control, reduce insulin resistance, and lower triglyceride levels. However, results vary, and more research is needed to determine optimal TRE protocols. Meal composition and timing are interconnected, with nutrient timing affecting satiety and appetite. Chronotype influences meal timing, with late chronotypes eating later and having higher calorie intake. Lifestyle factors, such as caffeine and alcohol consumption, also affect meal timing and energy intake. Artificial light exposure and sleep-wake patterns disrupt circadian rhythms, leading to changes in meal timing and increased energy intake. Sleep deprivation can alter meal timing and food intake patterns, while longer sleep is associated with earlier dinner times and reduced sugar consumption. Geography, religion, and social status influence meal timing and dietary habits, with cultural practices affecting food intake and cardiometabolic health. Overall, understanding the complex interplay between meal timing, circadian rhythms, and metabolic health is essential for developing effective interventions to prevent and treat obesity and related diseases.