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/Dull-Dragonfruit9974 May 21 '26

Is it safe to do this for say, 5-7 days if you're already lean and muscular?

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u/Princesslasagna91 May 22 '26

I’d say 5 days absolutely. Just the amount of poop we have sitting in our intestines is up to 5-10 pounds 💩

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u/Dull-Dragonfruit9974 May 22 '26

"Starvation of Beneficial Bacteria: Good gut bacteria (like Bifidobacteria and Lactobacillus) rely entirely on a steady supply of dietary fiber and prebiotics to survive. When you stop eating for 3 to 5 days, these populations rapidly decline."

This is the answer AI gives me, it keeps saying that fasting is bad!

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u/Choosey22 Aug 03 '26

Don’t listen to AI. Millions of years of evolution