Answer

In Jain history, there is no single fixed age at which a child must start doing Upavas.

Children in Jain families traditionally begin fasting only when they are physically able, mentally willing, and guided by elders or a Guru. Jain Dharma does not teach forcing children into Upavas.

Explanation

In Jain tradition, young children may begin with smaller forms of restraint before full Upavas, such as:

• Eating simple food
• Avoiding certain foods
• Doing Ekasana — eating once in one sitting
• Doing Biyasana — eating twice within limits
• Partial fasting
• Full Upavas when capable

The purpose is not to show physical toughness, but to develop:

• self-control
• discipline
• detachment from taste
• spiritual awareness
• reduction of passions

Spiritual Understanding

In Jain Dharma, Tapasya such as Upavas should be done with:

• right faith
• calm mind
• proper understanding
• health awareness
• guidance from knowledgeable elders or Guru

A child’s first step in Tapasya is usually small and gradual. Even if a child cannot do Upavas, learning kindness, truthfulness, avoiding unnecessary harm, doing Samayik, reciting prayers, and controlling desires are also meaningful spiritual practices.

Takeaway

There is no historically fixed age for Jain children to start Upavas. In Jain tradition, children may begin fasting gradually when they are capable, willing, and properly guided. The spirit of Upavas is self-control and purification, not pressure or compulsion.