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  • Writer's pictureby Karen Pike

Why I’m doing a 24 Hour fast to improve my gut health…and the many other health benefits of a fast.

As a student, I wrote an essay on intermittent fasting and the emerging research that has become popularised by the likes of TV doctor Michael Mosley. The science behind the health claims was fascinating. Reverse Type 2 diabetes? Improve longevity? Lose weight? Reduce your risk of dementia? And many more…

As someone who has a keen interest in gut health, I have recently discovered the work of Dr Mindy Pelz, who is a holistic health expert, well-known in the USA for her books on resetting your health through fasting.

The recent increase in scientific research around fasting has allowed us to understand just how it positively affects our physiology, cells, aging, disease and overall health. In 2016, a Dr. Ohsumi won a Nobel prize for his work on autophagy. Autophagy means “self-eating” and is the body’s way of cleaning out damaged cells in order to regenerate newer, healthier cells. Autophagy is the fast track to healing and slowing the aging process. And guess what? - fasting triggers the autophagy process. Essentially, fasting helps accelerate healing and gets your body to naturally repair itself!

So what happens to your body when you fast?

When you don’t consume food or calories, the body looks for other ways to generate energy, such as drawing on glucose stores. Once the glucose is significantly used up, the body’s metabolism changes and the body begins to burn fatty acids from stored fat for energy. When this transition to burning fat for energy is made, the body begins producing ketones and is said to be in a state of “ketosis”.

Once you reach ketosis, many of the benefits of fasting start to kick in. The specific benefits can vary depending on how many hours you have been fasting. For example, growth hormones kick in at 13 hours, whereas autophagy is thought to kick in at 16-18 hours. MIT research shows that at 24 hours intestinal stem cells will begin repair and 24 hours is also when you start to see weight loss.

So at 24 hours, you get the benefit of new stem cells in the intestine, which equates to repair. At this point, the body also eliminates any unwanted cells, including pathogenic bacteria and yeasts. So if you have dysbiosis, SIBO or impaired gut barrier, 24 hours seems like the magic number to help with this.

What does it feel like to fast for 24 hours?

As I write this, I am 21 hours into my 24 hour fast. I stopped eating last night at 6pm and will have my evening meal at this time today. I’ll admit it has been a bit uncomfortable not eating today, and I am definitely counting down the hours until I can eat again. I feel a little light-headed and my stomach is gurgling, but as I get towards the end of this fasting window, I actually feel a little lighter in my body and clearer in my head.

I’m going to aim to do this once a week to support my gut health. But there are many other different fasts that you can do to support your health, ranging from intermittent fasting (13-15 hours) right through to a 3 day fast. It has been reported from clinical trials that fasting up to 72 hours can re-set your entire immune system, as at 72 hours your stem cells for your immune system begin to regenerate – which obviously has huge potential benefit for cancer recovery and auto-immune conditions.

Which is the right fast for you?

Balancing your blood sugars through preparing your body for fasting AND getting your body used to fasting are both key, so starting with a 13 hour fast and building up from there seems a sensible way to get started. If you would like to read more about the work of Dr Mindy Pelz then her website is a great place to start -

NOTE: Please don’t try any of the longer fasts without advice from a doctor or a qualified nutritionist. If you would like to make an appointment to discuss how Viva Nutrition can support your health goals, then please get in touch at


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