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Naru’s Answers To The Top 10 Most Asked Questions About Intermittent Fasting.


1. Is it Healthy to Intermittent Fasting Every Day?


For most people, Intermittent Fasting (IF) it is one of the best FREE tools to use alongside good sleep, nutrition from whole foods, social connect, exercise, sunlight, nature, grounding, cold and hot exposure. Intermittent fasting has gained substantial attention for its potential health benefits. This is my 9th year of Intermittent Fasting and it is the perfect foundation for me to build all my other healthy behaviours on top off. Without it, I feel everything else is less effective.


Unlike traditional diets, IF is not a diet, it is a lifestyle that involves alternating periods of eating and fasting. You are not having to change what you eat, just when you eat it. You take the exact same amount of food you would normally eat and then eat it over a shorter period.

Obviously, you need to change other aspects of your lifestyle too, you cannot carry on sleeping, eating and not exercising and expect intermittent fasting to save the day!

For the majority of people


Research indicates that intermittent fasting can lead to significant health improvements, including weight loss, enhanced metabolic health, and better cardiovascular health. [1]


Regular fasting periods can reduce insulin resistance, lower oxidative stress, and promote cellular repair processes. [2]


Exceptions to the rule.


  • Women with a normal menstrual cycle, ideally after day 20 (20 days from day you started bleeding) you should reduce fasting to around a 13hrs or abstain from IF. If you add too much stress during this period, this will lead to the release of cortisol. Progesterone is a precursor to cortisol. This means that progesterone is needed to form cortisol in the body, causing progesterone levels to decrease when cortisol levels rise. It can cause symptoms such as fatigue, sleep disturbances headaches or migraines and menstrual irregularities.

  • Unstable Diabetes: Patients with unstable blood sugars and at risk of hypoglycaemia should exercise caution. Intermittent fasting is used in Type 1 & 2 diabetics every year during Ramadan. People with uncomplicated Type 1 Diabetes Mellitus (T1DM) can safely engage in intermittent fasting, like Ramadan fasting, provided they have structured education and advanced glucose monitoring systems. [3] 

  • Eating Disorders: Caution should be taken with history or current conditions like anorexia or bulimia.

  • Pregnancy: Nutritional needs are higher and fasting should not be done during pregnancy.

  • Chronic Kidney Disease: Changes in diet can impact kidney function and fluid balance.

  • Adrenal Insufficiency: Fasting is a stress on the body and could lead to adrenal crisis.



2. How Many Hours Should I Fast?


The length of time you are intermittent fasting for should mirror your goals. Research suggests that a fasting period of 14-18 hours can effectively promote fat loss and improve metabolic health. [4] It's crucial to choose a schedule that fits your lifestyle to maintain consistency and achieve sustainable results.


The number of hours fasting should be taken as rough guide, because everyone’s body is different and there is not a specific cut off.


If you are fasting for weight loss and you are losing weight, then I would suggest listening to your body and you are on the right track!

See our 28 Day Intermittent Fasting Challenge for some guidance on how to try different fasting times and schedules.


Here is a rough quick guide for you:


Basic Fasting – 13 hours:


-       Schedule: Stop eating 3 hours before bed, and don't eat until 2 hours after waking.

-       Benefit: Provides a simple structure to regulate eating habits.


16:8 Fasting:


-       Schedule: Stop eating at 8:00 PM, start eating at 12:00 PM the next day.

-       Benefit: Good for general health maintenance and weight control. It is also easy to maintain as a lifestyle.


18:6 Fasting:


-       Benefit: Promotes autophagy (cellular repair and cleaning). Suggested to consume low carb, low protein (<30g), and higher fat diet.


20:4 Fasting (One Meal A Day - OMAD):


-       Benefit: Effective for short periods to create a calorie deficit and support weight loss.


24-hour Fast (Gut Reset Fast):


-       Benefit: Helps in releasing stem cells and aiding gut repair.


36-hour Fast (Ketogenic Fast):


-       Benefit: Pushes the body into ketosis, which is beneficial for breaking through weight loss plateaus.


3. Can I Exercise When I’m Fasting?


Absolutely! Exercising in a fasted state can enhance fat oxidation and improve metabolic adaptations. [5] Initially, it's advisable to start with low-intensity activities and gradually increase intensity as your body adapts to fasting. Fasted exercise can be beneficial for weight management and improving insulin sensitivity.


However, it's important to listen to your body and ensure adequate hydration and nutrition during eating windows to support recovery and performance.


Exercise is one of our 3 ground rules when fasting. This is because exercise signals to the body that muscles are required and not food!

We have THREE GOLDEN RULES when fasting to avoid muscles loss:

1. Exercise when fasting – This involves any movement but especially weight training and cardio.

2. Consume optimal amounts of protein – 1.6 – 2.2g of protein per kg of body weight.

3. Optimise minerals - especially Magnesium and Zinc intake.


Top Tip


It is important that you are comfortable in your fasting window. Intermittent Fasting is a stress on the body and so is exercise. Make sure you are adapted well to your fasting window before you start to add either vigorous exercise or longer duration of exercise.


The great advantage to exercising in a fasted state is that your body is usually switching between fat and sugar stores already. This is the foundation of zone 2 training, because it allows the body to jump your stored fat stores for energy.


Zone 2 training is 180 – age = The max heart of that zone and you want to stay around that.


4. How Long Does It Take to Get Used to Intermittent Fasting?


Adapting to intermittent fasting varies among individuals, but most people acclimate within a few weeks. Starting with a longer eating window and gradually extending the fasting period can ease the transition. A study by Tinsley and La Bounty (2015) [6] suggests that the body typically adjusts to new eating patterns within 2-4 weeks, during which hunger levels and energy fluctuations stabilise.


5. Does It Matter If I Eat Early or Late in the Day?


Eating earlier in the day may have metabolic advantages due to circadian rhythms. Insulin sensitivity is higher in the morning, which facilitates better glucose metabolism. [7] Eating late at night can disrupt sleep patterns and impair digestion. Therefore, aligning food intake with natural circadian rhythms can enhance metabolic health and improve sleep quality.


“A good rule to stick to is avoid eating within two hours of waking and avoid eating three hours before bed. Then you can structure you’re eating windows around those metrics.” 


6. What Can I Eat and Drink During Fasting Times?


Ultimately, whether you choose to consume black coffee or black tea during intermittent fasting depends on your goals and personal preferences. Intermittent fasting is a lifestyle, so coming from someone who is 9 years into it, I prefer to do what gives me the results you want and ignore the rest.


If you're pursuing a more rigorous fasting approach, you might opt for plain water only.


However, many people find that incorporating black coffee or tea, electrolytes, salt, lemon water etc can enhance their fasting experience without undermining their overall objectives. The key is to avoid calorie-rich additives and maintain consistency with your fasting schedule.


Whether a particular substance or action "breaks a fast." What people are really trying to ascertain is whether these things interfere with or negate the benefits of fasting, such as:

  • Ketosis: If you want to stay in ketosis, you could have a ‘Bullet Proof Coffee’ or some MCT oil, however it was affecting autophagy and gut rest. Fasting is a rapid way to enter ketosis, a metabolic state known for its fat-burning properties, fat adaptation, and, in some cases, improved cognitive function by causing increase GABA release in the brain.

  • Resting the Gut: Stevia, salt, plain or carbonated water will be ok. The human digestive system exhibits daily rhythms in the secretion of saliva, gastric acids, digestive enzymes, and bile salts, as well as intestinal peristalsis, with reduced activity at night and increased activity in the morning.

  • Weight Management: Fasting, by virtue of not consuming calories, encourages the body to utilise its existing fat stores for energy. Many individuals also find that fasting helps them manage their calorie intake effectively.

  • Autophagy: This cellular process involves the removal of damaged components, sustaining cell function, and potentially slowing down the aging process. Fasting triggers autophagy, and ending the fast prematurely can halt this beneficial process. Protein content before your fast and when you break you fast is almost the largest determinant, protein content needs to be below 30g per day!


To summarise, during fasting periods, consuming water, electrolytes, black coffee/tea, or herbal teas is recommended to maintain hydration without breaking a fast.


When you break your fast, a balanced diet during eating windows should include a variety of nutrient-dense foods such as vegetables, fruits, unprocessed proteins, and healthy fats. [8] It's important to avoid high-calorie drinks and foods that can spike insulin levels and disrupt fasting benefits.



7. Can I Drink Alcohol During Intermittent Fasting?


Not during your fasting window because of alcohol’s effects on metabolism and its’ caloric density. Alcohol is calorie-dense and can inhibit fat oxidation, potentially impeding weight loss. [9] Avoid alcohol intake during your fast and swap it for some zero calorie flavoured drinks in the evening if you would like to sit down with a glass of something.


8. Why Am I Not Losing Weight on IF?


To lose weight means you need sleep, exercise, eat, socialise, work, and live a different life to the one you are currently living now! The life you are currently living, has led you to the weight you are now.


If you want to get the most out of IF, WHEN you eat and WHAT you eat will supercharge your results from IF.


Your pre-fast meal can help you to get the most out of your IF and your fast breaker meal will also help with weight loss. What do I mean? If you are fasting for ketosis (great for weight loss), then a low carbohydrate, moderate protein and a higher fat pre-fast meal will allow your body to transition into the ketosis more efficiently. If you want to remain in ketosis, the fast breaker meal should be ketogenic to make sure you are staying in ketosis once you have broken your fast.


Weight loss during intermittent fasting can be influenced by several factors, including total caloric intake, macronutrient composition, and physical activity levels. Keeping a food journal can help identify potential issues such as overeating during eating windows or consuming high-calorie, low-nutrient foods. [10]


One issue is that you may not be fasting for long enough to encourage your body to switch on metabolic flexibility and start to breakdown stored fat! 1lb of fat contains 3,500kcals, so your body will take a while to break it down.


Here are a few scenarios for you.


Scenario 1 – You are eating too many carbohydrates when you break your fast. Your pre & post-fasted meals are integral to your fasting outcomes.


Scenario 2 – You have not fasted for long enough to force your body into metabolically switching. Some people can benefit from a 36 hour fast or some people may need a more ketogenic based diet for a few weeks in combination with their fasting.


Scenario 3 – You may want to add in some exercise during your fasting window. If you add it in and your are not losing weight, workout harder and longer until you do!


Scenario 4 - You are eating rubbish in your fasting window. If you stop and switch your carrot for crisps, you will loose weight.

If you do not change your inputs, then your health will remain the same and slowly decline year upon year!

9. Do I Have to Stop Eating Out with Friends When Fasting?


Intermittent fasting offers flexibility, allowing you to adjust your eating schedule around social events. Planning and making mindful choices can help you enjoy dining out without disrupting your fasting routine. Research by Antoni et al. (2017) [11] suggests that maintaining a flexible approach to fasting can improve adherence and make it easier to integrate into a social lifestyle.



10. Can I Have a Cheat Day?


Intermittent fasting is not about strict food restrictions but about timing your meals. Occasional deviations from your fasting schedule, such as a "cheat day," can be managed without significant impact on long-term goals. However, it's important to remain mindful of overall dietary patterns and to return to your regular fasting schedule promptly. [12]


By integrating intermittent fasting into your lifestyle, you can experience numerous health benefits without the need for rigid dietary restrictions. Adapting these scientific insights can help you make informed decisions and sustain long-term health improvements.



1.    Patterson, R. E., & Sears, D. D. (2017). Metabolic Effects of Intermittent Fasting. Annual Review of Nutrition, 37, 371-393.

  1. Longo, V. D., & Panda, S. (2016). Fasting, Circadian Rhythms, and Time-Restricted Feeding in Healthy Lifespan. Cell Metabolism, 23(6), 1048-1059.

3.    Al-Ozairi, E. et al. (2019) Intermittent fasting could be safely achieved in people with type 1 diabetes undergoing structured education and advanced glucose monitoring, Frontiers. Available at: (Accessed: 29 May 2024).

  1. Mattson, M. P., Longo, V. D., & Harvie, M. (2014). Impact of intermittent fasting on health and disease processes. Ageing Research Reviews, 39, 46-58.

  2. Paoli, A., Bianco, A., Damiani, E., & Bosco, G. (2019). Effects of intermittent fasting on glucose and lipid metabolism. Current Diabetes Reports, 19(10), 61.

  3. Tinsley, G. M., & La Bounty, P. M. (2015). Effects of intermittent fasting on body composition and clinical health markers in humans. Nutrition Reviews, 73(10), 661-674.

  4. Morris, C. J., Yang, J. N., & Scheer, F. A. (2016). The impact of the circadian timing system on cardiovascular and metabolic function. Progress in Brain Research, 199, 337-358.

  5. Varady, K. A., Bhutani, S., Church, E. C., & Klempel, M. C. (2015). Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults. American Journal of Clinical Nutrition, 90(5), 1138-1143.

  6. Clevidence, B. A., Taylor, P. R., Campbell, W. S., Judd, J. T., & Vinyard, B. T. (2004). Lean and obese subjects' energy intakes during alcohol consumption in a controlled laboratory setting. American Journal of Clinical Nutrition, 80(5), 1180-1187.

  7. Harvie, M. N., Pegington, M., Mattson, M. P., Frystyk, J., Dillon, B., Evans, G., ... & Howell, A. (2011). The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women. International Journal of Obesity, 35(5), 714-727.

  8. Antoni, R., Johnston, K. L., Collins, A. L., & Robertson, M. D. (2017). Intermittent fasting: a dietary intervention for prevention and treatment of type 2 diabetes. Diabetes & Metabolism, 43(5), 362-371.

  9. Stote, K. S., Baer, D. J., Spears, K., Paul, D. R., Harris, G. K., Rumpler, W. V., & Ferrucci, L. (2007). A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults. American Journal of Clinical Nutrition, 85(4), 981-988.





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