<p>Fasting is abstaining from food and drink for spiritual purposes, and most religions, such as Islam, Christianity, Judaism, Hinduism, and Buddhism, practice it. This review article aims to highlight the growing body of evidence indicating that these traditional practices can significantly enhance health, spanning metabolic, cardiovascular, neurological, and psychological domains. This article also provides examples of how fasting regimens such as intermittent fasting in Ramadan, partial fasting in Lent, total fasting in Yom Kippur, and others have been shown to bring positive physiological changes like improved insulin sensitivity, lower blood pressure, and increased autophagy, which is a cellular repair process. Psychologically, fasting is linked to reduced stress and improved mood and thought processes, which can be enhanced because of its spiritual context. This article compares fasting practices in diverse religious traditions, highlighting commonalities and differences in fasting duration and style. Some risks, for example, dehydration, nutrient deficiencies, and overcompensation after the fast, are discussed, especially for vulnerable groups like pregnant women or diabetics. This review highlights how a religious fast can be seen as a form of contemporary health practice, while several gaps in current research are identified, such as long-term outcome data and individual differences. By scientifically analyzing individual spiritual practices, this paper informs public health policy and clinical applications while articulating an integrated perspective on how age-old practices may benefit modern health management.</p>