Here are the main reasons fasting is practiced in Jainism:

• Purification of the soul: Fasting helps reduce the influx of karmic matter by disciplining the body and senses, aiding inner purification.
• Self-control and discipline: By restraining food intake, a Jina practitioner strengthens mindfulness, willpower, and detachment from bodily pleasures.
• Reducing harm and violence: Less eating means less energy spent on activities that can lead to harm to living beings, aligning with ahimsa (non-violence).
• Penitence for past karma: Fasting is a form of penance to atone for past actions and to neutralize negative karmic effects.
• Spiritual focus: With fewer distractions from daily needs, the mind can concentrate on right faith, right knowledge, and right conduct.
• Humility and compassion: Fasting fosters humility, gratitude, and compassion for others who are hungry or suffer.
• Rites of special days: Fasting is commonly observed during auspicious periods (like Paryushan/Mahaparva) and during vrata (vows) to reinforce devotion and spiritual aspiration.
• Preparation for spiritual awakening: In Jain practice, deliberate austerities including fasting are seen as aids toward a higher state of spiritual awareness and detachment from the body.
• Detoxification of ego: By enduring hunger and discomfort, a practitioner works to weaken ego and attachments, moving closer to the ideal of pure consciousness.

Note: In Jainism, there are various forms of fasting (partial fasts, complete fasts, and structured vrata) and these can differ between Digambar and Shvetambar traditions in emphasis and practice. The core purpose, however, remains consistent: to purify the soul, cultivate discipline, and advance spiritual progress.