This FAQ is maintained primarily by @MmmBacon (Rob) and @Capnbob (also Rob). If you have a question related to fasting which you feel would enrich this compilation, please send it in a private message to @MmmBacon & @Capnbob and we’ll do our best to find the answer for you either referencing posts in the forum or third party websites. Please PM us too if you have any addition or amendment to any of the existing content and we will amend as necessary.
Please note that this Wiki is currently a work in progress. Questions will be added as and when time permits.
Disclaimer: Before embarking on any fasting regime it is important to discuss it with your healthcare professional. Proper hydration is essential for any type of fast and if you feel ill during a fast, stop and eat.
What is Fasting?
Fasting is the process of restricting dietary energy. The point is to signal the body to exit from a fed state into a fasted state, this reduces energy signals like Insulin, MTOR, and increases energy deficit signals like AMPK .
Why Fast?
Once your body is Fat Adapted (using Fat as it’s primary energy source as opposed to Carbohydrate) you may consider fasting in order to realise some of the benefits it provides, such as:
- Increased Insulin Sensitivity
- Autophagy (see What is Autophagy?)
- Higher levels of Ketone body production
- Weight loss
- Reduced inflammation
The biggest benefit of fasting is lower basal (fasted) insulin levels and increased insulin sensitivity. These effects tend to last. That means, every time you fast, you increase your body’s ability to deal with dietary glucose. Lower insulin means more fat burning power.
During fasting your body will use your stored body fat for energy, therefore reducing your weight. Over longer periods of fasting (see What is Extended Fasting?) a process of cell renovation called Autophagy is employed by the body to speed up the process of redistributing proteins from older cells to other parts of the body where new muscle growth is happening.
Ketone production is accelerated as more Fat cells are broken down for energy. Acetone, Aceto-acetate (AcAc) and Beta hydroxybutyrate (BOHB) Ketone bodies are released into your bloodstream and fulfil the role once performed by Glucose.
For some people fasting can be a spiritual process as well as a physical one, a time of renewal and calm. It is however rarely something which people can just start without a few challenges along the way. Both your mind and body will be adjusting to a new way of living which will raise all sorts of questions, hopefully many of which will be answered here in this FAQ.
What is a Fat Fast?
A fat fast is a specific kind of fast where you eat a small amount of fat to prevent your body entering caloric deficit, without stimulating the increase in Insulin or MTOR that the other 2 primary caloric energy sources (Carbohydrates and Protein) will stimulate.
What is a Water Fast?
A water fast is where you eat no calories, you just drink water to meet your thirst signals.
What is Autophagy?
Autophagy comes from the ancient greek word autóphago, meaning “self devouring”. It is a natural, regulated process of orderly degradation and recycling of cellular components and is a desirable outcome of Fasting due to its ability to regenerate human tissue on a cellular level. Studies have shown that Autophagy is accelerated by Fasting, therefore the cellular waste that is produced when we lose weight is recomposed into new tissue faster often resulting in less loose skin in areas of fat loss than would otherwise be the case. In order to maximise the effect of Autophagy during fasting it is essential to consume only liquids which have zero calories.
What is Extended Fasting?
An Extended Fast is generally a Fast which is longer than a 24 hour period and is typically 2-7 days, but some individuals may gain a benefit from fasting for longer still. Extended fasting durations should be built up over time by gradually extending the length of time you fast for much like you would build muscles by pushing them a little more each time you work out.
Notable mentions
The following forum members have contributed to the compilation of this FAQ.
@richard, @MmmBacon, @Capnbob, @alanwil2
We really appreciate all your efforts in making this a comprehensive and valuable resource.