Mixed

Fasting is defined as voluntary abstinence from some or all foods or beverages for preventive, therapeutic, religious, cultural, or other reasons, distinguishing it from starvation which is involuntary and pathological.

To fast, you voluntarily abstain from food and/or beverages for a specific period. This is distinct from starvation, which is involuntary and harmful. Your motivation (health, religion, culture) defines the context, but the core action is voluntary abstinence.