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What Can You Drink During Intermittent Fasting to Stay Hydrated?

What can you drink during intermittent fasting to stay hydrated? Plain water, sparkling water without sweeteners, and unsweetened black coffee or tea are the safe defaults for most fasting protocols. Calories, protein, and significant sweeteners break the fast for metabolic purposes—even if they technically contain water.

Water and electrolytes during the fasting window

Long fasts and low-carb eaters lose sodium and water quickly—headaches often mean electrolytes, not just H₂O. Compare with keto hydration and electrolytes and our electrolytes guide. Zero-calorie electrolyte powders are common; confirm they match your fasting rules.

What to avoid

Juice, milk, bone broth with calories, and diet sodas with sweet taste you are trying to avoid—all are debated, but purists stick to water and plain coffee. Full beverage context lives in water vs other beverages.

Feeding window hydration

Do not cram a day's water into two hours—spread intake across eating and fasting periods with TakeSip so headaches do not sabotage adherence.

Breaking the fast with fluids

When your eating window opens, start with water before heavy food—especially after 16+ hour fasts. Bone broth and electrolyte drinks may fit some protocols but check calories against your rules. Headaches during fasting often mean sodium, not just volume—pinch of salt in water helps some people without breaking fast. If dizziness persists, shorten the fast or consult a clinician.

16:8 vs extended fasts

Shorter daily fasts rarely need more than water and occasional salt. Multi-day fasts demand medical supervision and careful electrolyte planning—not blog advice. If you exercise fasted, hydrate before the session and accept slightly lower intensity until you adapt. Break fasts with water before food to reduce overeating rebound.