Fasting can be a way for the body to restore its balance and normal functioning. Over time, poor dietary habits may lead to the accumulation of excess fat and metabolic by-products, some of which may be unnecessary or harmful. Through fasting, these accumulations may be reduced, allowing the body to function more efficiently.
Contrary to common assumptions, fasting does not necessarily mean damage to the body or a predominance of breakdown processes (catabolism). Under certain conditions, fasting may support processes of recovery and metabolic adaptation, helping to restore physiological balance.
Metabolic Changes During Fasting
During fasting, several characteristic metabolic changes occur:
- mild metabolic acidosis
- a moderate decrease in blood glucose levels
These changes differ from those seen in certain pathological conditions (such as type 1 diabetes, kidney failure, or chronic respiratory disease), where acidosis is caused by the accumulation of toxic metabolic substances.
In fasting, acidosis mainly results from the use of the body’s internal energy reserves, especially fat stores.
Use of Energy Reserves
When external energy intake stops, the body begins to produce energy from its own reserves.
During fasting:
- approximately 80 – 90% of energy comes from fat stored in adipose tissue
- the remaining 10 – 20% comes from other internal sources
By using these reserves, the body reduces fat stores and helps eliminate some accumulated substances.
Ketosis – The Body’s Fasting Mechanism
The process through which the body begins to use fat as its main energy source is called ketosis.
During this process:
- fatty acids are metabolised in the liver and other tissues
- ketone bodies (ketones) are produced and become an important energy source
Ketones are produced when fats are converted into energy. They can supply energy to various organs, including the brain.
Blood Sugar Regulation During Fasting
During fasting, blood sugar levels tend to stabilise at lower values, usually around 60 – 65 mg/dl.
In this state:
- insulin secretion decreases
- insulin sensitivity may increase
This mechanism may help reduce insulin resistance, which is commonly seen in people with type 2 diabetes.
The Role of Lower Blood Sugar
Lower blood sugar levels may have a protective effect by reducing glycation.
Glycation is the process in which glucose attaches to proteins, altering their structure and function. High carbohydrate intake can accelerate this process.
By reducing carbohydrate intake and lowering blood sugar levels, fasting may help limit these effects.
The Role of the Liver During Fasting
The liver plays a key role during fasting.
Its main functions include:
- converting fatty acids into energy
- production of ketone bodies
- maintaining overall metabolic balance
Through these processes, the liver helps the body adapt to the temporary absence of food.
Rest for the Digestive System
Fasting also provides functional rest for the digestive system.
During this period:
- digestive movement decreases
- digestive secretions are reduced
digestive secretions are reduced To help eliminate remaining digestive residues, some fasting programmes recommend periodic enemas.
Conclusion
Fasting can be a method through which the body uses its energy reserves, regulates metabolism, and restores certain physiological balances.
By reducing food intake, the body activates adaptive mechanisms, including the use of fat as the main energy source and the stabilisation of blood sugar levels.
However, fasting should always be practised with care, responsibility, and awareness of each individual’s health condition.