In Jain dharma, eating onions is generally discouraged for religious reasons, but in practice:

• Ideally (according to Jain principles):

Jains are advised not to eat onions, garlic, or any root vegetables. Reason: - They are root vegetables – uprooting them kills the whole plant. - Many tiny living beings (micro‑organisms) around the root are harmed. This goes against Ahimsa (non‑violence), the main pillar of Jainism.

• In real life:

- Many strict Jains (both Shwetambar and Digambar) do not eat onion/garlic at all, at home or outside. - Some less‑strict or modern Jains, especially living abroad or in mixed families, do eat onions and garlic, even though it is not according to Jain ideals. - All Jain temples and proper “Jain food” places avoid onion, garlic and other root vegetables.

So, according to Jain dharma, Jains should not eat onions, but some do, out of habit, convenience or lack of understanding.