At 8am today I had a small bowl of porridge after a 60 hour water-only fast. Best bowl of porridge I've ever had! Oats, some chopped dried fruit, home-made soy yoghurt, and half a teaspoon of blackcurrant jam.

I see our digestive system as a 24/7 factory. With a fast we shut it down for a few days, so staff from the production line can focus on cleaning and maintenance. Then it slowly restarts, and functions better for it. Rubbish has been thrown out, bad habits broken, RSI rested, machinery oiled.

I can only speak from my experience, but I always feel great afterwards, and after my first ones twenty years ago with all the "toxin" symptoms (bad breath, spots, headaches) I don't have any negative effects any more. I do one every few years, and even during them I feel surprisingly energetic. I used to teach martial arts while fasting. At the end I reintroduce foods slowly, starting with plain and simple things like oats, rice, steamed vegetables. After a fast I have a much better relationship with food, since my body craves really simple and healthy stuff and no junk.

As an aside - I had one of the lowest sick rates in my departments when I worked for a uni. My occasional day off was usually due to injury rather than illness (snapped toe in martial arts; pulled back from helping a neighbour move heavy furniture). I used to have a normal amount of colds etc, but haven't actually had a cold or flu for maybe five years now, perhaps longer. So all I can say is that the way I practise it, and the frequency, seems to be a great thing for my body. (Some of that health may be from regular exercise, a vegan diet, and making good life choices.)

Also note that I am fasting partly as a bodily reset and chance for my body to switch the resources used for digesting food into other processes like cleaning and breaking down excess fats. I also partly do it as one of my willpower-strengthening exercises - saying "I can do this" and then just doing it. It's similar to my reasons for my recent week without chocolate and week without alcohol (and my challenges of getting up early to watch the dawn - see here and here). I am not doing it as part of a crazy diet or weight-loss system. For me it is something I do every few years, and I think it is one of many things that can help to maintain good health in a body that isn't malnourished. It works for me.

Humans did not evolve eating every day, yet our civilisation is based around endless food in large amounts (and often over-processed). It's rewarding to give up the luxuries and have a different experience.

In case you're curious: my longest fast is 74 hours, though that one was a water and fruit juice fast.

Where next? You might want to follow me and my work, or even buy my books. Many thanks!