In Jainism, fasting (known as upavāsa or tapa) is not considered "punishing" the body, but rather a method of spiritual purification and self-discipline. The practice of fasting is deeply rooted in Jain philosophy and serves several important purposes:

1. Reduction of Karma: Jains believe that fasting helps in burning past karmas and prevents the accumulation of new karmas. By controlling desires and abstaining from food, one reduces attachment and aversion, which are the main causes of bondage.

1. Self-Control and Discipline: Fasting strengthens one's self-control (samyama) and helps in mastering one's senses and mind. This self-discipline is essential for spiritual progress.

1. Detachment (Vairāgya): Fasting encourages detachment from material pleasures and bodily comforts, reminding practitioners of the impermanent nature of the body and the world.

1. Austerity (Tapa): Fasting is one of the six external austerities (bahya tapa) in Jainism. Austerity is a key practice for purifying the soul and progressing on the path of liberation (moksha).

1. Compassion and Non-violence: By eating less or fasting, a person minimizes harm to living beings, aligning with the central Jain principle of ahimsa (non-violence).

Importantly, fasting in Jainism should always be done with the right intention (bhāva), not out of compulsion or to harm oneself, but to purify the soul and progress spiritually. It is seen as an act of devotion, humility, and self-improvement—not bodily punishment.

References:

• "Tattvartha Sutra" by Acharya Umaswati
• "Jainism: An Introduction" by Jeffery D. Long