What's the longest fast you've ever done? Did You Know A 36-hour fast induces a shift from glucose to fat burning, enhancing mental clarity and initiating cellular repair. Evidence supports the idea that one 36-hour fast per week is enough to activate longevity-related pathways in most people, while a twice-weekly schedule may be appropriate for those who tolerate fasting well. Going beyond this does not appear to provide extra benefits and could create unnecessary risks. Longer-term randomized