Stay hydrated and salted during the fast

Drink water and replace electrolytes so fasting fatigue and headaches don’t derail you.

Why it works

Much of the "fasting feels awful" experience early on is dehydration and electrolyte shift, not lack of food — when insulin drops the kidneys excrete more sodium and water, which can cause headaches, fatigue, and lightheadedness. Replacing fluids and a little salt removes the main avoidable source of misery.

How to do it

1. Drink water steadily through the fasting hours, not just when thirsty.
2. Add a pinch of salt or an electrolyte drink if you feel headachy or foggy.
3. Don’t mistake dehydration for hunger — try water first when a craving hits.

Evidence

The electrolyte/fluid mechanism behind early fasting symptoms is well understood from renal physiology; direct trials on electrolyte supplementation for fasting comfort are limited. (mechanistic)

Adding salt is not for everyone — anyone with high blood pressure or kidney concerns should check with a clinician first.

Common mistake

Quitting fasting in the first week blaming "low willpower" when the real problem was dehydration and low sodium, which a glass of salted water would have fixed.