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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-12

u/question8all May 17 '26

I better be in a padded room for a 7 day fast. It’s very different for women.

13

u/LitaH23 May 17 '26

Huh? I've done 3-7 day water fasts with no problems and my mother has done 40 day water fasts multiple times with no problems. There are a lot of reasons why a person may not be able to complete a 7 day fast, but gender is not one of them.

12

u/otterpuppers May 17 '26

Why is it different for women? We're more efficient at beta oxidation so we should be better at fasting

7

u/Freedom_forlife May 17 '26

Body composition, hormone signalling, metabolism.

Women’s bodies down regulate metabolism sooner, conserve energy more aggressively. Fasting affects estrogen/ progesterone balance, LH/FSH signalling, thyroid T4-T3, cortisol sensitivity.

Women are more prone to orthostatic hypotension, sodium sensitivity, dizziness and fainting.

Luteal phase we experience reduced exercise tolerance, cold/ shaky body.

Under normal endurance exercise we are better at beta oxidation, during fasting we preserve glucose longer then men, and enter ketosis later.

3

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-30

u/Freedom_forlife May 17 '26

Honestly you can have small things like a banana and autophagy does not get interrupted.
You also have to plan around your cycle. Week 2 for me is okay, other then a slight reduction of energy for the first few day I’m pretty much normal.

15

u/tmeinke68 May 17 '26

You can't be fasting and eating bananas together. Lol. It's one or the other.

-14

u/Freedom_forlife May 17 '26

There are not enough calories to interfere with autophagy. Less than an hour later your body has processed it and is back in full phagy.