Answer

In Jain usage, Biyasana means taking food only twice in a day, and each time sitting in one place. It is a type of lay austerity, not a complete fast. In many Jain guides, it is also noted that sachitt items such as raw vegetables and raw grains are avoided in Biyasana. ( jainworld.jainworld.com)

Explanation

A simple common method of observing Biyasana is:

• Take a sincere sankalp / pachchakkhān in the morning.
• Eat only two times during the day.
• Eat both times while seated in one place.
• Do not take extra snacks or additional meals between those two sittings.
• Follow the diet rules of your tradition regarding sachitt and other items. ( jainworld.jainworld.com)

Spiritual Understanding

Biyasana helps develop restraint, simplicity, and control over taste and craving. Jain austerities are meant to reduce attachment to the body and support inner purity and spiritual discipline. ( jainworld.jainworld.com)

Takeaway

In short, Biyasana = two seated meals a day, with discipline and no extra eating. If it is being observed as a formal vow, it should be done according to your guru, family tradition, and health capacity. ( jainworld.jainworld.com)