On the Acidotic Crisis and Duration of Water Fasting


The first 5-8 days of prolonged water fasting are the most difficult. The hunger sensation disappears quickly (in the first 2-3 days), but weakness, nausea, and headache often appearlater on. These sensations subsequently pass, and fasting becomes comfortable. Why do unpleasant sensations go away and why is it important to wait for this moment without breaking the fast?

In the initialdays of fasting, the body uses up its carbohydrate reserves,particularly, liver glycogen, a process thatis accompanied by rapid weight loss. After using up most of the carbohydrate reserves, the intensity of weight loss decreases significantly, and the body begins to use up the fat. As you know, fat oxidation with an insufficient amount of carbohydrates is difficult. Undersuch conditions, when fat reserves arebeing consumed, products of its incomplete combustion,the so-called ketone bodies –acetone, acetoacetic and beta-hydroxybutyric acid–are formed, which contributes to the onset of acidosis, i.e. acidification of the blood. Due to a number of protective bodily mechanisms (in particular, the use of ammonia, formed as a result of protein breakdown, the presence of bicarbonate and other buffer systems in the blood), the acid-alkalinebloodbalance changes relatively little during fasting, i.e. such acidosis is always compensatedin humans. Therefore, the possibility of an acidotic coma (as, for example, in diabetes mellitus) is excludedduring therapeutic water-only fasting.

Nevertheless, in spite of all the compensatory mechanisms, acidosis increases during complete fasting in humans, usually reaching the maximum on the fifth or ninth day of fasting. This period is characterized by a significant drop in bloodalkaline reserves, an increase in ketone body contentin urine and blood, adecrease in blood sugar, and an increase in blood acidity. During the period of increasing acidosis, the patient may feel unwell, headache, nausea, depressed mood, various unpleasant sensations in the body and the smell of acetone from the mouth.

If fasting continues, there is a turning point that occurs within one day or even several hours: the indicators of acidosis drop sharply, as reflected in clinical and laboratory test results. In particular, acetone concentration in the expired breath condensate decreases (see Fig.).


Fig. Dependence of acetone concentration in expired breath condensate on the duration of fasting:
1 –volunteers with normal weight;
2 –patients with excessive weight;
3, 4 –patients with normal weight

(Source: I.B. Belyaeva. Clinical and laboratory assessment of efficiency of short-term courses of therapeutic fasting in the early stages of bronchial asthma. Summary of  dissertation for the degree of M.D., St. Petersburg, 1992)

At the same time, the patients condition improves dramatically: the mood becomes better, the feeling of weakness decreases, nausea and various unpleasant sensations in the abdomen disappear, the tongue gradually begins to clear of plaque, the complexion improves, the amount of feces excreted after an enema decreases, the rinsing water become clear, blood pressure gradually decreases. In the literature, this turning point is called the acidotic crisis. It is the sign of the body’s full adaptation to the complete fasting mode. The body has readapted and switched to endogenous nutrition, i.e. to using internal reserves to feed itself.

This restructuring is based on fat-sourced glycogen synthesis, which is not typical for a person with an ordinary mixed diet since sufficient quantities of carbohydrates are supplied with food. Fat oxidation is more complete in the presence of glycogen, it reduces the accumulation of ketone bodies and the acidotic shift, which is manifested in an improvement in well-being. After this switch to endogenous nutrition, a person can refrain from eating without any harmful consequences as long as he has energy resources. After switching to endogenous nutrition, the body begins to spend energy in the most reasonable way: general lethargy sets in, pulse and respiration become less frequent, peripheral vessels narrow down, and blood pressure slightly lowers.

After the body’s energy resources are consumed, the endogenous nutrition period ends, and realfasting begins, which quickly leads to tissue deterioration. The onset of this condition occurs individually, usually after 40-50 days of complete fasting.

Russian doctors who use fasting in patienttreatment (Yu. Nikolaev, A. Kokosov, I. Khoroshilov and others) attach great importance to the occurrence of the acidotic crisis during fasting. In their opinion, the main therapeutic effect of fasting and mobilization of the bodily defenses occurs after the crisis, therefore, they do not recommend interrupting the fasting process before it takes place. Some researchers (V. Zakirov, I. Khoroshilov, S. Osinin, G. Dorokhov, T. Demicheva) used combined fasting in order to accelerate the onset of acidotic crisis in patients with obesity and bronchial asthma. The combined fasting method includes three days of dry fasting followed by a wet fasting period. When this method is applied, the acidotic crisis occurs as early as 2-4 days from the beginning of fasting.

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