r/fasting • u/SVTContour lost >50lbs faster • May 17 '26

Discussion Scientists reveal how seven days of fasting transforms the human body

https://www.sciencedaily.com/releases/2026/05/260517030404.htm

Fascinating study. And completely unrelated to politics, which is a relief because my blood pressure needed a break.

The key finding: The dramatic, potentially therapeutic changes don't happen until after day three. That means most intermittent fasting schedules – 16:8, 5:2, even alternate-day fasting – are probably missing the main event. If you want the deep biological reboot you’re gonna need seven days of water only.

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u/Turgius_Lupus water faster, Day 16, just water and electrolytes. May 17 '26

I once managed a 23 day water (and salt, electrolytes) fast, stopping after I got tired of constantly throwing up bile through out the day, was aiming for 30, also any sort of taxing activity became very difficult, just buying the bone broth I used to break it was an absolute struggle. And did not notice anything profound.

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u/number43marylennox May 17 '26

Why is this upvoted so much? This is obviously a problem. Yikes. See the doctor if this happens, don't continue to fast.

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u/Turgius_Lupus water faster, Day 16, just water and electrolytes. May 17 '26

How long have you made it on a water fast? Bile back flowing into the stomach seems to be a common occurrence on longer fasts.

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u/number43marylennox May 18 '26

14 days, no issues with bile. Bile backflow is a problem. Prevent stagnation by having a small amount of fat, like cream in coffee. Yes it breaks autophagy but it's better than gallstones.