What are the Benefits of 36-Hour Fasting?

The concept of forgoing breakfast, lunch, and dinner for an entire day might seem overwhelming to many.

However, for Rishi Sunak, the UK’s Prime Minister, this is a regular part of his weekly routine.

Sunak undertakes a 36-hour fast every week, consuming only water, tea, or black coffee from Sunday evening to Tuesday morning.

While this might appear to be an extreme practice, experts suggest that this fasting regime could offer significant health benefits.

But is fasting just a health fad, or is it a safe and effective path to wellness?

Let’s delve deeper into these questions.

Is Fasting a Health Fad?

Fasting, particularly intermittent fasting, has gained popularity in recent years, often touted as a quick fix for weight loss and improved health.

However, it’s essential to note that fasting is not a new concept.

It has been practised for centuries for various religious, health, and even political reasons.

The science behind fasting suggests that it can lead to several health benefits, including improved metabolic health, increased longevity, and better brain health.

Therefore, while it might seem like a health fad due to its recent surge in popularity, fasting is a practice with deep historical roots and scientific backing.

Is Fasting Safe and Effective?

The safety and effectiveness of fasting can depend on various factors, including the individual’s overall health, the type and duration of the fast, and how the fast is conducted.

In the case of Rishi Sunak’s 36-hour fast, experts suggest that it could lead to a metabolic shift from using carbohydrates for fuel to using fat, potentially leading to improved metabolic flexibility and resilience.

However, it’s crucial to approach fasting with caution.

It may not be suitable for everyone, particularly those with certain health conditions, pregnant individuals, and people with a history of disordered eating.

Therefore, it’s always recommended to consult with a healthcare professional before starting a fasting regime.

The 5:2 Diet

Adam Collins, an associate professor of nutrition at the University of Surrey, has drawn an intriguing comparison between Rishi Sunak’s fasting approach and the popular 5:2 diet.

The 5:2 diet involves individuals restricting their calorie intake for two days of the week while eating normally for the remaining five days.

Collins suggests that Sunak’s 36-hour fasting regime is essentially a more stringent version of this diet.

The Prime Minister’s approach involves complete abstinence from food for a continuous period of 36 hours every week, consuming only water, tea, or black coffee during this time.

However, James Betts, a professor of metabolic physiology at the University of Bath, provides a crucial distinction between the two approaches.

He emphasises that a restricted calorie diet does not put the body into a fasted state.

This is a significant point, as the physiological state of fasting triggers a series of metabolic changes in the body.

In contrast, Rishi Sunak’s 36-hour fasting approach does put the body into a fasted state.

During this period, the body depletes its usual energy stores of carbohydrates and begins to burn fat for energy.

This metabolic shift can potentially offer a range of health benefits, including improved metabolic flexibility and resilience.

From Carbs to Fat

Under normal circumstances, the body primarily uses carbohydrates as its main source of energy.

However, during a prolonged fast, the body exhausts its usual energy stores of carbohydrates and begins to tap into fat reserves for fuel.

This shift from carbohydrates to fat, as explained by Collins, could lead to what he terms as “metabolic flexibility.”

This is the body’s remarkable ability to switch between different types of fuels depending on availability.

The benefits of this metabolic flexibility extend beyond just fuel utilisation.

It can result in “metabolic resilience,” a state where the body becomes more adept at handling the pressures of a modern diet and lifestyle.

This includes coping with periods of overeating, inactivity, or stress.

Potential Benefits of Fasting

One of the intriguing potential benefits of fasting is its ability to trigger autophagy, a cellular process that can be likened to a spring cleaning of the body.

Autophagy is a natural process in which cells deconstruct and recycle their components.

During a 36-hour fast, as the body depletes its usual energy stores, it may initiate autophagy as a survival mechanism.

This process involves the breakdown of old, damaged cellular components, which are then recycled and used to generate new, healthy cells.

This cellular rejuvenation might explain some of the apparent benefits of fasting for ageing and DNA repair, contributing to overall health and longevity.

However, it’s important to note, as Collins does, that these effects and the claims that fasting can lead to a longer life are largely based on animal research.

It’s unclear whether these benefits can be achieved with a 36-hour fast once a week in humans.

Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, offers a crucial perspective on the practice of fasting.

He advises that those who decide to embark on a fasting journey should be mindful of their eating habits during non-fasting periods.

Maintaining a balanced diet and avoiding overcompensation during non-fasting periods is key to reaping the benefits of fasting.

As Professor Sattar suggests, the goal should be to create a sustainable, healthy eating pattern rather than swinging between extremes of fasting and overeating.

In the end, the journey towards health and wellness is a personal one, and fasting can be a powerful tool on this journey when used wisely and appropriately.