This chapter examines the effects of Ramadan fasting on sleep and metabolic health, focusing on how changes in daily routines during the fasting period influence sleep patterns, sleepiness, circadian rhythms, and metabolism. It discusses the role of altered eating schedules and lifestyle during Ramadan in affecting sleep quality and architecture, noting that these factors, rather than the act of fasting, are likely to cause changes in sleep patterns. The chapter also addresses the importance of maintaining regular routines, such as consistent mealtimes and light exposure, to support the synchronization of the internal clocks of the body and prevent metabolic issues. The text presents findings that suggest that controlled lifestyle factors during Ramadan help preserve the circadian system’s integrity. It emphasizes the critical role of meal timing in metabolic health, proposing that adhering to the religious practice of eating around dawn and dusk during Ramadan can enhance metabolic health and stabilize circadian rhythms. The chapter highlights the importance of consistent daily practices during Ramadan to safeguard against sleep disturbances and circadian disruptions and improve the health benefits of the fasting practice. It concludes that well-regulated fasting and lifestyle adjustments during Ramadan can positively impact sleep and metabolic health.