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Ketone Bodies and the Benefits of Long-Term Fasting

Barbara Philipps - 24/06/2024 - 0 comments


Ketone Bodies and the Benefits of Long-Term Fasting

Our bodies are naturally designed to switch between periods of eating and fasting. During fasting, when we consume very few calories, our bodies start to burn stored fat for energy. Part of this fat is converted into ketone bodies, which are special energy molecules. These ketone bodies not only fuel our brain but also play a crucial role in triggering the body’s regeneration and repair processes.

The research team at the Buchinger Wilhelmi clinics has just published an eagerly awaited study on the role of ketone bodies and the benefits of long-term fasting in the scientific journal Nutrients.

In this article, we provide an overview of the topic and explain the main findings from the study.

Fat burning and ketosis: The body’s energy storage

The human metabolism is fuelled by sugar (glucose) and fat (lipids). When we eat more than necessary, our body stores the excess as fat, much like storing extra fuel in the trunk of a car. During fasting, the fat cells release the stored calories into the bloodstream, where they are distributed to the body’s cells, nourishing them from the inside. In our car analogy, this is like the driver using the reserve fuel instead of stopping at a gas station.

This “fasting metabolic programme” kicks in soon after we stop eating, mobilizing our fat reserves. It is comforting to imagine our body fat gradually melting away until we end the fast. People in industrialized countries usually have abundant body fat, and losing some is often seen as beneficial.

However, the situation is a bit more complex than that. While most tissues (such as skeletal muscles, heart muscle, kidneys, liver, etc.) can immediately turn fat into energy, others, like the brain, cannot use fats directly as fuel. To solve this, the liver converts fats into smaller molecules called ketone bodies in a process known as ketosis.

Over time, the central nervous system adapts these ketone bodies, specifically beta-hydroxybutyrate and acetoacetate, for use as fuel. Recent studies have shown that ketone bodies have a stabilizing and regenerative effect on the brain, earning them the nickname of “superfuels”.

Key discoveries from the study

This extensive study monitored 1,610 participants who underwent the Buchinger Wilhelmi fasting programme for between 4 and 21 days with a daily caloric intake of 75 to 250 kcal. The research meticulously examined fasting ketonemia (blood ketones) and ketonuria (urine ketones) and correlated these metrics with the metabolic improvements observed in participants.

Measuring ketosis with our FASTING BOX

The foods in our FASTING BOX are very low in calories and carbohydrates but high in fats, with some proteins, which helps your body to enter ketosis quickly. Our scientific team tested the FASTING BOX in a randomised controlled trial. The results are still pending publication, but we can already tell you that all the participants in this clinical study switched rapidly to ketosis as showed below using ketone test strips to measure ketone bodies in the urine (see chart).


This new study provides compelling evidence that long-term fasting can be safe and highly beneficial. By harnessing the body’s natural fat-burning ability, fasting can lead to significant health improvements.

The study underscores the potential of customising fasting to individual needs, making it a powerful tool for those with metabolic challenges. By understanding and utilising ketosis, our doctors can help patients achieve significant health benefits, including an improved body composition, better blood sugar control, and enhanced antioxidant defences.