What can I drink on a water-only fast?
Plain water only in strict mode. No bouillon, no coffee with cream, no supplements with calories. Caloric additions break a strict water-only fast.
Water Fast Timer
Water-only fasting means plain water — no coffee, tea, bouillon, or electrolyte powders with calories. It is the strictest form and best suited to shorter durations for most people. Use this timer only when you have already chosen water-only on purpose.
How to use this
- Choose water-only or assisted fasting and pick your goal hours.
- Tap Start fast when you finish your last bite. When you reach your goal, we show how to break the fast with meal ideas.
- Stage labels mark educational time windows only — they do not prove biological processes occurred.
Optional: Dr. Boz Ratio (glucose ÷ ketones)
Formula: glucose (mg/dL) ÷ ketones (mmol/L). Interpretations are educational only — not diagnostic targets. See our ratio guide for limitations.
Breaking an extended fast (19–35h)
After a longer fast, your digestive system may need a gentle restart. Start with protein, fat, and fiber in a moderate portion — not a feast.
How to break your fast
- 1Optional first: warm bouillon or bone broth — especially after water-only fasts.
- 2First meal: protein-forward and low carb. Aim for ~15–25g protein with healthy fat.
- 3Include gentle fiber: leafy greens, cucumber, or broccoli — not a huge raw salad right away.
- 4Eat slowly and stop at comfortable fullness — your hunger signals may be sharper than usual.
- 5Resume your normal low-carb eating window. Skip dessert and processed carbs for this first meal.
What to avoid
- • Breaking your fast with fruit juice, smoothies with banana, or sugary yogurt.
- • Large portions — treat this like two small meals 30 minutes apart if needed.
- • Heavy cream coffee with sugar — black coffee or tea is fine if you already tolerate it.
Tips
- A moderate protein-and-fat meal with gentle fiber is a common refeed pattern after longer fasts.
- If you feel lightheaded before eating, a small amount of broth or water may help — seek care if symptoms persist.
- Optional glucose/ketone tracking after eating is for personal observation only; it is not a diagnostic test.
Suggested break-fast meals
All recipesbreakfast
Scrambled Eggs with Spinach
Quick high-protein breakfast with minimal net carbs. Blood-sugar-friendly start for keto and insulin resistance meal plans.
~2g net carbs · 18g protein
lunch
Chicken Salad Lettuce Cups
Creamy chicken salad served in crisp lettuce wraps — low carb, high protein, no bread required.
~3g net carbs · 28g protein
dinner
Baked Salmon with Broccoli
Simple sheet-pan style dinner rich in omega-3s and protein with about 6g net carbs per plate.
~6g net carbs · 34g protein
breakfast
Low Carb Egg Muffins
Make-ahead egg cups with cheese and veggies — grab-and-go breakfast for busy mornings.
~2g net carbs · 12g protein
lunch
Ginger Chicken Bone Broth Soup
Light refeed soup with collagen-rich broth, shredded chicken, and ginger — about 3g net carbs. Gentle option after assisted fasting.
~3g net carbs · 18g protein
Not medical advice. This timer tracks clock time only. Talk to your doctor before fasting — especially on diabetes, blood pressure, or kidney medications. Do not adjust medication on your own.
Fasting timer
Who should avoid water-only fasts
Pregnancy, eating disorders, type 1 diabetes, and many medication regimens make water-only fasts unsafe without direct medical supervision. When in doubt, use assisted fasting or skip extended fasts entirely.
If you take diabetes or blood pressure medication, start with fasting on diabetes medications — not this timer.
Shorter vs longer water fasts
Many practitioners treat ~24 hours as an upper bound for unsupervised water-only fasts. Beyond that, electrolyte depletion and refeeding risks rise — read water fast vs assisted fast and prefer the extended fasting clock in assisted mode when cleared.
Exiting a water-only fast
Refeed gently. Broth and eggs beat pizza. Follow how to break a 24-hour fast even if your fast was shorter than a full day — stomach enzymes still appreciate a soft landing.
Related guides
Frequently asked questions
Is water-only safe for 48+ hours?
Extended water-only fasts beyond 24 hours increase electrolyte imbalance risk for many people. Discuss with your doctor; this timer may suggest assisted mode for longer goals.
How do I break a water fast safely?
Break with small portions of protein, healthy fat, and gentle fiber — not a large carb-heavy meal. Go slowly to reduce refeeding risk on extended fasts.
Other calculators
Metabolic Low Carb Calculator · https://metaboliclowcarb.com