Fasting Tracker
Calculate your fasting and eating windows for popular intermittent fasting protocols.
Protocol benefits
Most popular protocol. Sustainable for most people. Supports weight management, blood sugar control, and is easy to implement by skipping breakfast.
Greater metabolic benefits than 16:8. Good for those who have adapted to 16:8 and want more fat-burning time. Requires skipping breakfast and keeping dinner early.
Advanced protocol. One large evening meal plus small snacks. Strong autophagy induction. Not recommended for beginners or those with blood sugar issues.
One meal a day. Maximum autophagy. Difficult to sustain long-term. Requires careful nutrient density in the single meal. Not suitable for everyone.
Two very-low-calorie days per week (500–600 cal). Normal eating the other five days. Less disruptive to social schedules. Research-backed for metabolic health.
Frequently asked questions
Does coffee or tea break a fast?
Black coffee and plain tea (no milk, sugar, or cream) are generally considered to not break a fast as they contain negligible calories and may even enhance fasting benefits by suppressing appetite and supporting autophagy. Adding milk or sweeteners breaks the fast.
Can I exercise during a fast?
Yes. Many people train fasted — particularly low-intensity cardio. However, high-intensity or strength training near the end of your fast (before your eating window opens) allows you to refuel and recover with food promptly. Listen to your body, especially when starting.
Is intermittent fasting safe for women?
Women may respond differently to intermittent fasting than men. Some women experience hormonal disruption with aggressive protocols like OMAD or 20:4. Starting with 14:10 or 16:8 and monitoring energy, sleep, and menstrual cycle changes is advisable. Consult a doctor if pregnant or breastfeeding.
What can I eat during the eating window?
No foods are technically forbidden, but fasting is most effective when the eating window contains whole, nutritious food — lean protein, vegetables, whole grains, and healthy fats. Overeating junk food during the eating window negates most benefits.
How long before I see results from intermittent fasting?
Most people notice improved energy and reduced hunger within 1–2 weeks. Weight changes become visible in 4–8 weeks. Metabolic benefits (blood sugar, cholesterol) may take 2–3 months of consistent practice. Consistency matters more than the specific protocol.
Note: Consult a doctor before starting any fasting protocol, especially if you have diabetes, low blood pressure, a history of eating disorders, or are pregnant.