On Ātham (8th tithi), many Jains follow extra saiyam (restraint) in food. Practice can differ by city, sangh, and whether you follow Śvetāmbār or Digambar, but the general idea is:

1. Vegetables on Ātham (common practice)

- Many Śvetāmbār Jains: - Avoid green leafy vegetables (saag, palak, methi, coriander leaves, etc.) on Ātham and sometimes also on Chaudas. - Some stricter families avoid all vegetables on Ātham and eat only grains–dal–fruits, or do upvās / ayambil. - Digambar Jains: - Often treat Ātham as a strong upvās / pakhi day; many will fast or take very simple food. Details differ by local maryādā.

1. Things almost always avoided (every day, not only on Ātham)

- Root vegetables (kand-mool): potato, onion, garlic, carrot, beet, radish, ginger, fresh turmeric, etc. - Any non‑veg, eggs, honey. - Fermented items are often reduced or avoided on tithi–upvās days.

1. Why this restriction?

- On important tithis like Ātham and Chaudas, Jains try to: - Reduce violence (himsa) to tiny life‑forms. - Keep body and mind lighter for sāmāyik, pratikraman, punya. - Greens and certain vegetables are believed to involve more living beings; avoiding them is an additional vow of care.

1. What you should do in practice

- Follow your family / guru / local derāsar maryādā, because tithi-rules are tradition-based, not identical everywhere. - If your home follows “no vegetables on Ātham,” then keep only simple food: grains, dal, non-root spices, fruits, etc., or observe upvās.

For a simple Jain food guide you can read more here