The body initiates a sequence of physiological shifts when we abstain from food during fasting. On an episode of my podcast, I explore this with Dr Sepp Fegerl of the world-famous VivaMayr medical health resort in Austria. Here’s a look at some of the profound ways in which this age-old practice impacts our system.
To truly understand the effects of fasting on our body, it’s crucial to consider its evolutionary roots. Our forebears, shaped by cycles of feast and famine, evolved sophisticated physiological responses to these variable conditions.
Today, amidst a backdrop of constant caloric availability, fasting serves as a bridge to these ancient adaptive systems, potentially paving the way for improved health. A 2019 study from Germany’s Buchinger Wilhelmi clinic revealed that extended fasts ranging from four to 21 days significantly reduced body weight, blood pressure, blood sugar levels, and abdominal fat, while also elevating physical and emotional well-being.
What happens when we fast?
Fasting sets off a chain of reactions that impact multiple systems within the body. “As an individual refrains from caloric intake, the most immediate effect is the depletion of glucose reserves in the bloodstream and the liver. In search of an alternative energy source, the body turns to its glycogen stores, breaking them down into glucose molecules to sustain basic metabolic functions. But glycogen reserves are finite, and as the fasting period persists, the body pivots towards a more sustainable source of energy—fat. Through a process known as lipolysis, adipose tissue releases fatty acids into the bloodstream, allowing tissues and organs to derive their energy from these lipid reserves,” says California-based Dr Ronesh Sinha, internal medicine physician, author of The South Asian Health Solution, and an expert on insulin resistance.
More than just cutting calories
Fasting isn’t just another diet trend; it’s a journey that takes our body through intricate biological pathways and even reshapes our cognitive terrain.
The risk of nutrient deficiencies is a significant concern when considering fasting, underscoring the importance of a well-planned and balanced approach. Dr Fegerl illustrates this point vividly: “Imagine that you start fasting and you’re already suffering from a deficiency in trace elements that are key in the enzymatic performance of your liver, such as selenium, zinc or copper, for example. That person’s body – especially the mitochondria – suddenly works on alternative metabolic strategies. They try to compensate for the deficiency, and increase the risk of developing a myocardial infarction (stroke) or the aggravation of a mental illness.”
Before embarking on a fasting journey, it’s paramount to seek expert guidance to ensure safety and efficacy.