For how many days can a person survive without food?
A person can survive about 10-12 days without food. That’s the time limit before any eventual damage will accumulate and threaten life.
This is assuming you’re otherwise in good health, with some body fat to spare which makes a significant difference for how much energy is stored. Assuming you are not compromising your immune system with chronic lack of sleep or extreme stressors, it would take weeks or months before a person would be at risk from various infections that way either (the skin microbiome changes dramatically after just 3 weeks of starvation).