Yes — within Jain spirit, I can suggest a simple self-designed upavās / austerity vow that remains rooted in ahimsa, aparigraha, and self-restraint.

A proposed fast: Laghu Sādhana Upavās

A gentle fasting vow for one day:

Rules

• Eat only one time before sunset.
• That meal should be simple, sattvic, and minimal.
• Avoid all green vegetables, roots, and heavy foods.
• Refrain from sweets, fried food, and unnecessary indulgence.
• Keep mind, speech, and body शांत:

- no anger - no gossip - no unnecessary speech - no entertainment

• Spend time in:

- samayik - pratikraman - jap / contemplation - reading Jain sutras or stotras

Optional stricter version

• Eat only plain boiled food once
• Or take a complete upavās until the next sunrise, if the body and mind permit

Inner intention

The real purpose is not only hunger control, but:

• reduction of passions
• purification of the soul
• increase in self-discipline
• practice of non-attachment

Important Jain principle

A fast should be taken with humility, faith, and proper capacity, not out of pride or harm to the body.

If you want, I can also create a more specific Jain-style fast for:

• a beginner
• Paryushan
• a monthly fast
• a fasting vow with samayik and pratikraman