Intermittent Fasting Questions Answered: The 20 Most Common Q&As

Most people start intermittent fasting with a list of questions and nowhere reliable to get honest answers. This page answers the 20 most common ones — clearly, without jargon, and based on what actually works.

If your question is not on this list, browse the full Q&A library or submit your question and the community will answer it.

Getting Started

1. What exactly is intermittent fasting?

Intermittent fasting is an eating pattern where you cycle between a fasting period and an eating window. You choose a daily window during which you eat — typically 6–8 hours — and fast for the remaining 16–18 hours. It is not a diet in the traditional sense: you are not told what to eat, only when. See what is intermittent fasting for the full explanation.

2. What is the most popular protocol?

16:8 — fast for 16 hours, eat within an 8-hour window. For most beginners this means skipping breakfast and eating between noon and 8 PM. It is the most well-researched protocol and the easiest to sustain long-term.

3. How do I start if I have never fasted before?

Do not jump straight to 16 hours. Start at 12:12 (12 hours, which is basically overnight), then move to 14:10 after a few days, then to 16:8 once that feels easy. The full step-by-step process is in how to start intermittent fasting for beginners.

4. Is intermittent fasting safe?

Yes, for most healthy adults. It is not recommended during pregnancy, breastfeeding, with a history of eating disorders, or with type 1 diabetes without medical supervision. See is intermittent fasting safe for beginners.

Breaking the Fast

5. Does black coffee break a fast?

No. Black coffee has essentially zero calories and does not trigger an insulin response. It is one of the best fasting companions — it reduces hunger and improves mental focus. Milk, sugar, cream, or flavoured syrups do break the fast. See does coffee break intermittent fasting.

6. Does diet soda break a fast?

Technically the calories are near-zero, but artificial sweeteners may trigger a small insulin response in some people and tend to increase cravings. For best results, stick to water, black coffee, or plain tea during the fasting window.

7. Can I have gum or mints while fasting?

Most gums and mints contain sugar or sweeteners that can trigger a response. Sugar-free gum in very small amounts is unlikely to break a fast meaningfully, but it is best avoided if you want clean results.

8. What can I drink during a fast?

Water (still or sparkling), black coffee, and plain herbal or green tea. Anything with calories, sweeteners, or milk breaks the fast. See what can you drink during intermittent fasting.

Hunger and Side Effects

9. How do I handle hunger while fasting?

Hunger comes in waves — it peaks and then passes within 20–30 minutes if you do not feed it. Drink water first (most "hunger" is thirst), have black coffee if needed, and distract yourself for 20 minutes. The hunger almost always subsides on its own. See how to handle hunger during intermittent fasting.

10. Why do I feel dizzy or get headaches when fasting?

Usually dehydration or electrolyte loss. Your body excretes more sodium when insulin drops, so drink more water and consider adding a small pinch of sea salt. In the first few days, this also happens when you extend your window too quickly — slow the progression down. See electrolytes and intermittent fasting.

11. Is it normal to feel tired in the first week?

Yes. Your body is transitioning from primarily burning glucose to accessing fat as fuel. This takes 5–10 days and can cause temporary fatigue. Push through the first week — energy typically improves significantly once the transition is complete.

Weight Loss

12. Will intermittent fasting help me lose weight?

Yes, for most people. It works by lowering insulin (which allows your body to access stored fat), naturally reducing calorie intake without counting, and improving metabolic health overall. Results typically appear within 2–4 weeks of consistency. See how long to see results with intermittent fasting.

13. Do I need to count calories?

No. Intermittent fasting works through hormonal changes, not calorie arithmetic. Eat satisfying meals within your eating window and trust the process. See do you count calories on intermittent fasting.

14. Can I eat whatever I want during my eating window?

You will get results eating almost anything within a reasonable eating window, but results accelerate when you cut sugar and processed food. Think of food quality as the accelerator — not required, but it helps significantly.

Exercise and Lifestyle

15. Can I exercise while fasting?

Yes — and many people find their best workouts happen fasted. Light to moderate exercise works well during the fast. For intense training, eating a proper meal shortly after is fine. See can you exercise while intermittent fasting.

16. What is the best time to work out on 16:8?

Most people on 16:8 (eating noon to 8 PM) find training at 11 AM or noon — right before or at the start of the eating window — works best. You train fasted and immediately refuel afterward.

17. What do I do in social situations?

Adjust your window on social days rather than skipping fasting entirely. If you have dinner at 7 PM, eat your first meal at 1 PM — you still get a 17-hour fast. See intermittent fasting in social situations.

The Mental Side

18. Do I need willpower to fast?

Much less than you think — and it gets less every week. Hunger is largely hormonal, not a test of character. Once insulin levels stabilise (usually after the first 1–2 weeks), fasting becomes genuinely easy for most people. See does intermittent fasting require willpower.

19. What if I break my fast by accident?

Nothing is ruined. Pick it back up the next day. One slip does not break the habit — stopping entirely because of one slip does. Treat each day independently.

20. How do I know if intermittent fasting is working?

Look beyond the scale: improved energy, better focus, reduced hunger, fewer cravings, better sleep, and clearer skin are all common early signs. Body composition changes follow. Most people notice something positive within the first week.

Have a question not on this list? Browse the full Q&A library — hundreds of community questions, all answered. Or submit your own and get a personal answer.

Want the complete guide? Intermittent Fasting in Practice by Mehrdad Jamshidi covers all of this in depth — plus the mindset, social strategies, and practical frameworks that make fasting sustainable long-term. Get it on Amazon and claim 3 months free app access.

Frequently Asked Questions

Where is the best place to get intermittent fasting questions answered? FastingInPractice.com has a growing library of hundreds of answered questions — both editorial articles and community Q&As. You can search by topic, browse by category, or submit a question that has not been answered yet. It is completely free.

How long does it take to get a submitted question answered? Most submitted questions are answered within a few days by the community. Popular questions are turned into full editorial articles with detailed answers.

Is the content on FastingInPractice based on science? Yes. All answers draw from peer-reviewed research and the protocols in Intermittent Fasting in Practice by Mehrdad Jamshidi. The site does not publish opinion as fact.

This article is for informational purposes only and is not medical advice. Always consult a qualified healthcare professional before starting any fasting protocol, especially if you have an existing health condition.