Why I plan to fast periodically during 2014

Intermittent fasting: The good things it did to my body generated a huge response when it was published on the BBC News website. It was the conclusion to a 3-part series looking at my experience as a volunteer in a clinical trial at the University of Southern California. 

I want to thank everyone who responded with comments, questions and stories of their own experiences following similar regimes. I plan to continue down the path of self experimentation (always heeding the advice of medical professionals), by adopting a fasting lifestyle and modifying my diet.  The science continues to evolve - and there is much that is not fully understood - but I am personally persuaded that there is strong evidence that a periodic fasting regime coupled with sensible food options during non-fasting periods, could have a significant impact on my long-term health and longevity. 

In the coming months I will blog about my experiences and I will try to answer some of the questions raised by my original BBC articles (see earlier posts). I will tell the stories of other people who took part in the USC trial and follow the study through to its conclusion.  I will continue to interview the scientists and reflect their views - as well as the opinions of others.

It is my intention to continue this year with a 5-day fast (as outlined here) - repeated every two months. So that's 5 days out of 60 when my calorie consumption will drop to about a quarter of my usual intake. I will write in more detail about the experience as it unfolds.  The first 5-day fast will start on Sunday (Jan 19).  The goal is to experience, over a longer period of time, the effects of period fasting and to evaluate its feasibility as a lifestyle. I will blog about how it makes me feel and what it does to my general state of health.

In the coming weeks I will write about issues such as weight loss and gain while following this diet. During the trial I regained weight after the fasting period, but this does not mean that the regime failed. Volunteers were encouraged to return to a 'normal' diet and their original weight. My goal, over a longer period, is the see whether sustained weight management is possible. 

I will also look at the issue of exercise while fasting.  This was one of the most common questions.

Intermittent Fasting vs Periodic Fasting

Taking the lead from Dr Valter Longo, Director of the USC Longevity Institute, I plan to refer to this as a periodic fast, rather than an intermittent fast. The latter term has become synonymous with the current spate of fasting regimes and is often used as an umbrella expression for a range of diets which involve breaks in food intake - such as the 5:2 diet and alternate day fasting.

Periodic Fasting occurs over a longer period (several days) but less frequently (once a month or every few months).  Hopefully this will help distinguish what I am doing from the intermittent fasts which have become popular. I will return to this topic, to expand on the science, and to explore how periodic and intermittent fasts differ. 

The following Tweet from the BBC News Magazine prompted many varied reactions. 

Would you eat this five days a month if you thought you'd live longer?

My simple answer is;  yes, I would. This is spinach soup (other ingredients include mushroom, celery, olive oil, kale, nettle, nutmeg and cumin). It was tasty and not that dissimilar to the soups your grandma may have made. When was the last time you prepared fresh soup at home?  It was just one element of a range of soups and other foods designed to offer limited calories but high quality nutrition. Note, this food is currently experimental and not yet available commercially. 

"Live longer?" - perhaps it should have read, "...stay healthy longer?"   The goal is to live better, for longer, rather than spend my final years fighting the typical diseases of old age.