Fasting, also referred to as Intermittent Fasting (IF) and Time Restricted Feeding (TRF), is simply the manipulation of your eating and/or fasting windows. We’ve shared in detail about the practice of, benefits of and research behind TRF before and in this article we cover the frequently asked questions related to implementation.
When fasting, how many hours constitutes a fast?
Believe it or not, you’re already practicing a form of fasting. The period between your breakfast and lunch is a fast. The period between your dinner and breakfast would also be considered a fast. However, for the real benefits of TRF or IF to occur the attention should be directed toward the fasting that takes place overnight, between the last bite on one day and the first mouthful the next day. This is referred to as the ‘overnight fast’.
For digestive ease and to strengthen appetite control, at The Natural Nutritionist (TNN) we recommend a minimum 12 hour overnight fast. It’s typically very practical and for most, a realistic place to start. It means fasting from 7.30pm until 7.30am the next day and finishing dinner by 7.30pm. As the fasting muscle strengthens and 12 hours overnight becomes a breeze, the circadian rhythm fast is the next step and requires a 13 hour overnight fast followed by an 11 hour eating window (13:11).
The progression of 13:11 is the 16:8 protocol in which a 16 hour overnight fast is followed by an 8 hour eating window. Research shows this is by far the most protective form of IF from a disease risk point of view and so once your fasting muscle is well and truly strengthened, at TNN we recommend introducing 16:8 on two days of the week.
Anything longer than 16 hours would be considered less of a standard practice and we recommend working one on one with your Nutritionist or health care professional to determine if a longer fast or more frequent fasting is suitable for you.
When fasting, can you have a morning snack?
Technically speaking, achieving a pure fast means no calories should be consumed during the fasted period. It would mean between dinner and breakfast only water and herbal tea could be consumed – nothing else. In saying this, it’s an area in which little research has been done, so the consensus is mixed, and it does depend on the intended goal.
When should I practice pure fasting?
For the anti-aging benefits of autophagy, zero calories are considered best. This means it’s water, black coffee, black tea or herbal tea during the fasted period. If the goal is fat loss and there’s a significant amount to be lost, then zero calories would also likely support the best results.
When should I include some calories during the fasted period?
You may be suited to including some calories during the fasted period if you’re female of childbearing age, brand new to the practice of fasting or are intending to lose weight more steadily (and less rapidly). A small number of calories from fat in the form of coconut oil, flaxseed oil, butter, ghee or MCT oil during the fasted period does technically break the fast, yet it isn’t likely to induce a large insulin response (or derail the goal of fat burning). It will however help to curb cravings for those new to the practice, therefore making the fasting period more comfortable and enhancing compliance.
Fats are crucial for hormone production, so for healthy hormone balance in females of child bearing age, those with adrenal fatigue or thyroid challenges we don’t recommend pure fasting in the majority of cases. Try consuming fats in the form of our MCT Coffee, Anti-inflammatory MCT Coffee or the Dairy Free MCT Coffee.
What about having a tea with milk during the fast?
As you now know, to achieve a pure fast having calories during the fasted period is not considered allowed. Whether its cow’s milk, sweetened almond milk, coconut milk or most other milks, milk contains calories which means it wouldn’t be suited to a pure fast. In saying that, for the purpose of fat utilisation, very small amounts of unsweetened almond or coconut milk during the fast may still allow some to achieve results.
If you are including these milks in the fasted period and aren’t achieving the desired results, it’s possibly a sign that you’re ready to do without them and need to consider the pure fast (outlined above).
Can non-calorie sweeteners be had during the fast?
Stevia, erythritol and xylitol are all examples of non-calorie sweeteners which leads some to consider them to be appropriate during a pure fast. However, even though calorie free, the sweet nature of these ingredients triggers specific receptors on the tongue and initiates an insulin response. This isn’t ideal as an insulin response is to be avoided in order for the many benefits of TRF and IF to be gained. If you crave sweetness, allow some of these non-calorie sweeteners in the diet but have them during the eating window rather than the fasting period.
What about fasting and training?
It’s not unhealthy or dangerous to exercise at a light to moderate intensity for 20 – 60 minutes before having breakfast. It’s referred to as fasted training and the benefits of such training include increasing aerobic capacity and supporting fat utilisation (the use of fat for fuel).
For those new to fasted training, particularly females, we recommend starting with shorter sessions (20 – 45 minutes) and having an MCT Coffee prior. This provides ~250 calories and still counts as fasted training for the purpose of fat utilisation.
When training fasted, especially for sessions greater than 60 minutes or those with intensity, the ideal window for refuelling is within the 60 – 90 minutes post training, so this needs to be factored into your overall fasting period. In other words, fasting should not be done at the expense of training recovery. This means fasting on a rest day or timing training so the post training meal can be had at the end of the overnight fast is required.
For many, higher intensity sessions such as HIIT, strength or interval training can also be done in the fasted state. These sessions require greater carbohydrate utilisation and tend to support a goal of muscle growth; which is why for others, performance and recovery may be enhanced when food is consumed prior.
If the concept of fasted training is entirely new to you, begin with your shorter and lower intensity sessions before extending the practice to your longer and higher intensity sessions.
Should I be scared about fasting?
Never before have we as humans had such ready access to food. Could you imagine your great grandparents shopping the snack isle at their local store? Do you believe early humans had access to food 24 hours a day, 52 weeks of the year? Allowing periods of fasting, even as short as 12 hours, is simply bringing us closer to a state in which we as humans would’ve spent most of our years on this earth.
In saying this, there are certainly groups in which IF should be avoided or only considered under the guidance of a health professional. This includes:
- During pregnancy or breast feeding.
- During periods of high stress and/or adrenal dysfunction.
- If you are takin certain medications, including insulin.
- If you have poor blood sugar control. As always, start with real food first and improve your satiety and metabolism before your dive in the deep end with TRF.
- After high intensity training and extended aerobic sessions, as discussed.
Post your questions below so we can keep the conversation on IF and TRF going. If you’d like tailored support book in for your complimentary 15-minute consultation today.