Fasting, as a common practice in mystic schools, has a special status due to religious obligation it demands, its constructive nature, and its role as the first step in spiritual aspiration. In the context of mystical thought, and due to interpretive and spiritual quality of mysticism, fasting goes beyond the boundaries of superficial religious interpretations, expands its meaning and finds a meta-religious stance, so that sometimes attention to religious fasting itself defiles such meta-religious fasting. The dialectic/interactive structure of mysticism which, in the process of presence and absence, constantly exposes the phenomena to "becoming, " is comprised of three common mystical principles and patterns: religion, spirituality, and truth. In this structure each concept or category is an element or component which, immediately, gains an interpretive dimension and can be placed under the principles of religion, spirituality and truth with different semantic dimensions. A diachronic and historical study of fasting reveals that in the early stages of mysticism and Sufism, what matters most for mystics is the religious aspect of fasting. In recent years, however, the practice of fasting has come to exhibit a closer relationship with interpretation, in alignment with its three-partite structure. In this article, we review the various approaches to fasting in prominent mystical texts and analyse the similarities and differences among these approaches in a structuralist reading.