Fasting: What´s it about?

Fasting, refraining from food for a certain period, is trending. Various fasting methods are claimed to bring about diverse health benefits for body and mind. But what’s the truth behind the healing effects, and how do different fasting types differ? And is intermittent fasting a miracle cure for health? We delve into the fasting phenomenon.

Where does it come from?

Fasting is mostly known to people through the fasting period following Carnival in spring. During this Christian tradition, various foods such as animal products and alcohol are abstained from for 40 days. Detached from the church, the concept of abstinence has also made its way into society. Many people are motivated to fast, especially for health reasons. Some abstain from alcohol, sweets, coffee, fast food, or meat. Currently, it is particularly popular to refrain from any food intake for a certain period, with various practices such as full or intermittent fasting. The promises of healing through abstinence are diverse, ranging from anti-inflammatory effects to cellular rejuvenation. But what is really true?

Full Fasting

During full fasting, solid food is completely avoided for a specific period (often between 3 and 21 days). During full fasting, only clear fluids such as water, unsweetened herbal teas, and possibly diluted vegetable broths are typically consumed. This fasting should be carried out under medical supervision or following thorough instructions to avoid nutrient deficiencies and other risks.

Intermittent Fasting

Intermittent fasting (also known as interval fasting) involves regularly alternating between eating and fasting periods. There are various methods, of which 16/8 and 5:2 are the most well-known. With the 16/8 method, one eats within an 8-hour window and fasts for the remaining 16 hours of the day. With the 5:2 fasting, one eats normally on 5 days of the week and significantly reduces calorie intake on the other 2 days (about 500-600 calories per day). This method promotes flexibility in eating habits and can have positive effects on weight management since fewer calories are consumed overall. Some evidence for a reduced risk of common diseases such as cancer, cardiovascular diseases, Alzheimer’s, or diabetes has been shown in animal studies, but it’s not universally applicable to humans. Meaningful, controlled long-term studies in humans are needed to learn more about the actual health effects.

The Miracle of Fasting? Current state of research

Myth of Alkaline Fasting

Alkaline fasting aims to balance the body’s acid-base balance. Acid-forming foods such as meat, fish, dairy products, coffee, and alcohol are avoided. Instead, the focus is on alkaline-forming foods, mainly fruits, vegetables, and whole grains. Alkaline fasting is often touted as a miracle cure for various health problems, but the scientific basis for this is more than questionable. Our body regulates the pH value very effectively itself, and the idea that we can fundamentally influence our acid-base balance through certain diets is a myth. The “evidence” that alkaline fasting actually brings the promised effects such as detoxification or improved health often comes from qualitatively questionable studies and is considered not secured. Similarly, alkaline dietary supplements can be dispensed with, as their effectiveness is not supported by any scientific evidence.

Possible Side Effects of Fasting - What You Should Pay Attention To

In general, fasting poses no risk to healthy adults. However, deliberate food deprivation can sometimes be accompanied by unwanted side effects, including headaches, circulatory disorders, bad breath, flatulence, or even sleep disturbances. Therefore, it is particularly important to ensure adequate fluid intake during fasting to minimize the risk of these manifestations. Another side effect is weight loss. However, fasting is not suitable as a long-term weight loss method, as there is no sustainable change in eating habits, and the yo-yo effect usually occurs shortly after returning to normal eating habits.