Water Fast Coaching and Nutritional Therapy

Why water fasting elicits powerful detox

There are countless diets, techniques and fads designed to help you detox. Many of these can certainly help, but if you’re really serious about cleansing, it’s also important to take an entirely different approach: through the practice of water fasting (or, alternatively, dry fasting).

Why? Because by sustaining a period of zero caloric intake, you can shift the body into a fundamentally different metabolic state. A number of physiological changes take place during fasting, and these can be thought of as occurring in two broad stages.

(1) Autophagy and a break from digestion

The first level of cleansing begins after your body has finished digesting its last meal. In this respect, what you eat impacts considerably. While most fruit and vegetables require only a few hours to digest, meals containing more fat and protein generally take significantly longer.

Digestion itself also consumes energy, in order to physically move food through the GI tract (peristalsis) as well as generate the enzymes required to break food down into its constituent nutrients. The heavier the diet, the more energy required to complete this process. In particular, the digestion of protein requires a lot of energy, demanding 20-30% of the calories contained in the given meal.[1]

When you stop eating, however, digestive activity naturally decreases, and the energy normally required for digestion can be directed elsewhere. Along with this, the body’s metabolism begins to shift towards using stored energy, given that the body is no longer actively processing a continual stream of food.

Taking a break from digestion also triggers autophagy: the process of degrading and eliminating cellular waste. If ‘detox’ can be defined as ‘the process of removing poisons or toxins from the body’,[2] then the autophagy triggered by fasting clearly constitutes a crucial step in this larger process of detoxification. Studies have shown that this upregulation of autophagy begins within the first 16-24 hours of fasting,[3] and can lead over the long term to lower LDL cholesterol levels and reduced inflammation markers such as CRP (C-Reactive Protein).[4] [5]

By definition, juice fasts and other cleanses which involve eating cannot achieve this to the same extent. Not only do they contain calories which reduce the need to depend on stored energy, but they also activate digestion, stimulating enzymes and peristalsis. Even simple juice triggers peristalsis. I have observed this among numerous clients when they break a water fast with juice: the end result often being a bowel movement within an hour or two.

(2) Fasting ketosis and fat-soluble toxins

The second, and in many ways deeper, metabolic shift begins once your body moves towards the fat-burning metabolism called ketosis. Described in greater detail in the articles about one-day water fasts and three-day water fasts, this process generally takes place after glycogen stores become depleted. This threshold is typically reached 24-36 hours after the onset of fasting. My clients who measure their blood or breath ketones regularly confirm this, also noting that ketone levels tend to rise through the first 5 days of fasting, after which they more or less plateau out.

Ketosis is important because it represents a fundamental change in the fuel your body is using. Rather than relying primarily on recently consumed food and stored glycogen, the body increasingly draws on stored fat. This is also the metabolic environment in which a number of fasting-related cellular processes become more active, including pathways associated with autophagy and cellular recycling, as noted in the section above.

One reason that fasting ketosis is so important for cleansing is that fat-soluble (lipophilic) toxins such as PCBs are normally sequestered and stored in adipose tissue (fat cells).[6] This keeps the given toxins out of the blood and body tissues, where they would otherwise cause damage. Over the long term, however, continued exposure means that the intracellular levels of such toxins can only rise.

The study cited above (Jandacek et al) demonstrated that rapid weight loss – such as that which would occur through fasting ketosis on a water fast – releases these toxins from adipose tissue into the blood. From here, the liver plays a crucial role in detoxification. Technically, this takes place especially through Phase I detoxification pathways in the liver, using enzymes such as cytochrome P450 (CYP)[7] to convert fat-soluble toxins (including PCBs) into water-soluble molecules, for subsequent elimination from the body.

In short, by drawing on fat cells for energy, fasting ketosis facilitates the release of fat-soluble toxins (such as PCBs) into the blood, for processing and elimination by the liver.

Fasting ketosis versus dietary ketosis

Some people following ketogenic or very-low-carbohydrate diets make the argument that ketosis itself provides the same cleansing benefits as fasting. There is certainly a metabolic overlap: both fasting ketosis and dietary ketosis increase fat utilisation and produce ketones. During a ketogenic diet, however, you are still eating, digesting and providing the body with an ongoing supply of nutrients and energy. (I explore this issue further in my video: Fasting Ketosis vs. Keto Diets: Why They Are Not the Same.)

As the study cited above also notes: it is specifically the element of rapid weight loss which triggers the release of intracellular fat-soluble toxins. This does not happen with dietary ketosis, which under normal circumstances assumes a relatively stable weight – in contrast to fasting ketosis.

So while dietary ketosis and fasting ketosis share important features, I would certainly not regard them as interchangeable. In fact, I repeatedly observe that clients who have followed long-term ketogenic / low-cqrb diets prior to their fasts tend to take longer to present with detox symptoms such as headaches or nausea during their fasts, as compared to clients who have followed lower-fat diets beforehand (typically 3-5 days as opposed to 2-3 days). This isn’t to imply that headaches and nausea are necessary side effects of every fast, but when they do present, the timing suggests to me that the pre-fasting diet itself must play a role in how quickly the body is able to make the metabolic shift into deep ‘cleansing mode’. I personally suspect that, given the liver’s leading role in emulsifying and digesting dietary fat, ketogenic diets effectively tie down a lot of the liver’s overall metabolic energy in a digestive role, which would likely put the liver at a disadvantage at the beginning of a fast.

This may have longer-term implications as well. Although it is impossible to establish a direct causal relationship, one widely cited observational study published in The Lancet Public Health (2018) found an association between very low carbohydrate intake and increased mortality, noting a possible decrease in lifespan of up to 4 years.[8] (The same study also noted a similar excess mortality to those following a very high carbohydrate intake.)

The time to fast and cleanse is now!

Unless you happen to live far from human civilisation, the air you breathe is likely to contain pollutants and carcinogens. Unless you drink straight from a mountain spring, the water you drink almost certainly contains added chlorine, along with the residue of microplastics, industrial waste products and hormones from the contraceptive pill – none of which cannot be fully filtered out by municipal water treatment plants. Unless you eat fully organic, your food was probably grown with the use of pesticides, fungicides and fertilisers. If you eat meat and dairy products, many farmers also treat their animals with antibiotics and artificial growth hormone. If you’ve recently been taking pharma drugs, your body may also contain metabolites from medication.[9]

The bottom line is that, like it or not, we face near constant exposure to chemicals and compounds which do not belong in our body.

I hope this is a wake-up call.

For me, the answer is fasting. I see the results with my clients. And as a practitioner I also experience it myself first-hand..

My Story

When I first tried out my very first water fast, I was shocked by what came out of my body. My breath stank. My sweat stank. My urine stank. My tongue turned a pasty white and began to literally froth, producing a bitter, metallic taste in my mouth lasting for days. I didn’t know exactly what physiological processes were taking place in my body, but I didn’t have to. It was utterly foul. And because it was so foul, it also felt good to eliminate it all from my body.

From that point on, I began to honour my body with regular fasting. And over the first couple of years of practice, I went from being the first person in the family to catch colds to being the last. As much as fasting was always a challenge – and even after all these years it’s still a challenge! – it also felt rewarding. It felt like I was getting closer to being able to listen to my body. And when deep in a fast, I began to find increased mental clarity and peace of mind.

Despite knowing the benefits, however, it’s all too easy to sit on the fence, knowing and feeling that you should fast, and yet not quite reaching the point of actual commitment. It might be anxiety about hunger and detox symptoms. It might be your work schedule. Who knows. We all have our reasons, and it’s easy to find an excuse. If you need help in making that final step towards a water fast, I’m here to support you as a water fasting coach.

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[1] https://www.healthline.com/nutrition/negative-calorie-foods#fact-vs-fiction

[2] https://www.webmd.com/vitamins/ai/ingredientmono-1179/detoxification

[3] Herzig S, Shaw RJ. AMPK: guardian of metabolism and mitochondrial homeostasis. Nat Rev Mol Cell Biol. 2018 Feb;19(2):121-135. doi: 10.1038/nrm.2017.95. Epub 2017 Oct 4. PMID: 28974774; PMCID: PMC5780224

[4] Anson RM, Guo Z, de Cabo R, Iyun T, Rios M, Hagepanos A, Ingram DK, Lane MA, Mattson MP. Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proc Natl Acad Sci U S A. 2003 May 13;100(10):6216-20. doi: 10.1073/pnas.1035720100. Epub 2003 Apr 30. PMID: 12724520; PMCID: PMC156352

[5] Shimokawa I, Higami Y, Utsuyama M, Tuchiya T, Komatsu T, Chiba T, Yamaza H. Life span extension by reduction in growth hormone-insulin-like growth factor-1 axis in a transgenic rat model. Am J Pathol. 2002 Jun;160(6):2259-65. doi: 10.1016/S0002-9440(10)61173-X. PMID: 12057928; PMCID: PMC1850833

[6] Jandacek R, Liu M, Tso P. Interactions of Body Weight Loss with Lipophilic Toxin Storage: Commentary. J Nutr. 2024 Mar;154(3):801-803. doi: 10.1016/j.tjnut.2024.01.018. Epub 2024 Jan 18. PMID: 38244860; PMCID: PMC10942849

[7] Roach, C.M., Koester, N.R., Li, X. et al. 3,3′-Dichlorobiphenyl (PCB 11) alters the hepatic expression of cytochrome P450 enzymes in the liver of mouse dams exposed orally during pregnancy and lactation. Arch Toxicol 100, 943–957 (2026). https://doi.org/10.1007/s00204-025-04241-7

[8] Seidelmann S, Claggett B, Cheng S et al. Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis. The Lancet Public Health, 2018; 3, e419-e428

[9] https://www.thefreedomcenter.com/how-long-does-it-take-for-a-drug-to-be-cleared-from-the-body/

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