Fasting is considered a healthy measure to relieve the body, to lose some weight and to consciously deal with the issue of nutrition. However, uncontrolled fasting, not medically supervised therapeutic fasting or a zero diet can bring side effects and in certain cases even become dangerous. What happens in the body during fasting and who should not fast?
Lose weight by fasting?
Weight reduction is not the main focus of fasting, but is only a positive side effect. If you want to achieve a weight reduction in the long term, you should also change your diet in the long term following fasting. In addition a fiber-rich, but fat-poor food, which makes full and by which the fat reserves are diminished slowly but surely, belongs. Otherwise the feared “Jojo effect” threatens after the end of the chamfering cure. Healing chamfering can be however an impulse for a change of the life-style. The positive experiences of a therapeutic fasting cure can contribute to the fact that the entire Lebensführung becomes more health-conscious and the nourishing habits are changed
Side effects of therapeutic fasting
Therapeutic fasting is usually performed under medical supervision in fasting clinics. The change of metabolism and hormone balance during therapeutic fasting is also accompanied by psychological changes. Feelings of increased alertness and concentration as well as an increased sense of well-being are mentioned. Mild side effects may include low blood pressure (hypotension), fatigue, dizziness, lack of concentration, increased sensation of cold and dry skin. Furthermore, body odor, bad breath and menstrual disorders have been observed. The unpleasant odor is caused by the secretion of ketones through the breath and sweat. These are produced during fat burning. Particularly thorough body and oral hygiene can help here. The aforementioned side effects usually normalize in the course of fasting. Stronger side effects that can occur as a result of fasting are:
- Acidosis and gout: the increased acetone produced with increasing duration of fasting causes hyperacidity, ketoacidosis, as well as the unpleasant odor due to the excretion of ketone bodies through urine and breath. This process inhibits the ability of the kidney to excrete uric acid, resulting in an increase in uric acid concentration in the blood serum.
- Elevated uric acid levels: people whose uric acid levels are already elevated (hyperuricemia patients) should not fast because of the risk of an acute attack of gout.
- Protein breakdown: Furthermore, the brain can use the ketone bodies when fasting for several days, however, only after a few days. Therefore, in the initial phase of fasting, the organism increasingly breaks down the body’s own protein from the skeletal and cardiac muscles (about 75 grams per day) to form glucose from amino acids (gluconeogenesis).
When does fasting become dangerous?
Particularly dangerous is the muscle breakdown of the heart muscle, myocardium. This degradation can occur due to the breakdown of the body’s own protein during fasting. Especially in the case of heart problems, fasting is therefore not without danger. During very rapid weight loss, even with some protein intake, there may be a significant mobilization of body protein from the myocardium. This is especially true for people of normal weight or only slightly overweight, who lose more fat-free body mass, i.e. muscle, during fasting than people who are very overweight. Longer-term fasting (more than five days) is also questionable due to the lack of supply of vital fatty acids, vitamins and minerals. Prolonged fasting should therefore be carried out under professional guidance. The following individuals should therefore fast only under medical supervision:
- People with severe obesity
- People with depressive disorders
- People with diabetes mellitus type 1 or 2 or hepatitis
- People who have recently survived a serious illness
- People with duodenal or gastric ulcers.
Who should not fast under any circumstances?
Although most adults tolerate fasting well, certain groups of people should avoid fasting for health reasons. Should not fast at all:
- Pregnant women and nursing mothers
- People with certain heart, liver or kidney diseases
- Cancer patients
- Children
- People with eating disorders
- People with hyperthyroidism
- People with addictive disorders
- People with dementia
As a general rule, if you have any doubts about your health suitability or experience unusual or severe side effects during fasting, you should always consult a doctor.