I’m doing my next 5 day fast and this time I’m using the new generation of fasts from Prolon, which has liquid soups that are a major improvement on previous iterations. Some of you may know I have been working on my metabolic health for many years. Many years I hear you say – why bother! But in that time I have been learning a lot of things.

My last blog on this topic, mentioned that on the previous 5 day fast I wasn’t able to lose any weight. Since then I have been training my body in metabolic flexibility through intermittent fasting and crucially if I was able to measure it bringing my insulin down and improving insulin resistance. Going from those overnight fasts 7am-7pm then a few longer fasts each week of 14-16 hours has been training my body. So much so that this time coming into the 5 day fast I have adapted to the fast much quicker.

Not that it’s easy as one still tends to feel hungry most of the day. But interestingly, this time I am able to measure my ketones having been gifted a ketone machine by Keto Mojo at the Integrative and Personalised Medicine Conference. Last night my ketones were 0.1 which is normal in the non-fasted state, but by this morning my ketones were 0.4 suggesting I am moving into nutritional ketosis. It will be interesting to see what happens over subsequent days and whether that might rise to above 0.5. I’ve already lost 0.5kg from day 1-2 and this may again reflect that my insulin resistance has been improving over the subsequent six months with the intermittent fasting. But here is the rub: my cholesterol is still raised although my healthy lipids have gone up and my less healthy lipids have gone down so I might still not be advised to take a statin.

So I guess this whole thing about metabolic health is not easy to manage and many of you may have found yourselves as you move through the decades gaining weight, gaining abdominal circumference, finding your lipids are out of whack and that you might be moving into prediabetes. One of the conclusions I am coming to is that I might need to live with a very low carbohydrate diet. In September we will be launching a new teaching programme for the medical undergraduates: ‘Lets Go Keto’. Not because we think everyone should be on an ultra low carb diet but just that doctors of the future need to understand the range of what a low insulin lifestyle can look like and how to support people’s metabolic health.

I am gradually reaching my target weight and abdominal circumference but still need to look at my lipid profile and in order not to slip back I’ll need to be proactive with all the elements that I am learning about. But learning about ketones has been of great interest to me and how nutritional ketosis can mean your ketones are elevated but your glucose is not, which is very different from the pathological state of ketoacidosis where ketones run wild in the context of very high blood sugars. With the help of my colleagues Dr Ian Lake and Pauline Cox, learning to differentiate these elements will be important for the medical students to create safe doctors knowledgeable in lifestyle medicine. I’ll let you know how I get on and whether I get to the end of this 5 day fast in another blog.

If this is a topic that interests you, here is a link to a recent podcast with Don Gordon a functional nutritionist who specialises in fasting and also a link to an accredited course on fasting:

#02 The Fasting Reset: Integrative Tools for Inflammation and Longevity – NCIM – National Centre for Integrative Medicine

Introduction to Integrative Medicine – Part 2 Fasting for Longevity, Wellness and Lifespan (Accredited)

We’re also excited that from September we’ll be able to support members of the public with 5 day fasting with the help of the NCIM team and in partnership with L-Nutra who with Prof Valter Longo has developed the science of the fasting mimicking diet.

Dr Elizabeth Thompson