SIX things I have Learnt from forty-hour Fasting

As readers of my blog will know, I am keen on the science of nutrition and on the fascinating revelations about our gut-biome – so it may not come as a surprise that I have been dabbling in intermittent fasting. The science behind it seems pretty solid, though the evidence can seem a bit subjective unless you are part of a proper test where all functions and levels are being measured.

So I have been doing the easiest of fasts to achieve, that is still shown to be effective in triggering the benefits, that is: 16 – 18 hours. My chosen day to begin is a Sunday, after a good lunch-time Roast dinner with dessert, and a lighter tea-time meal. So, from 6pm Sunday evening – no food until at least 10am on Monday – but often it runs to noon. Easy – as for half of it you are asleep!

No food – but I allow myself drinks – water, obviously, but also a very small glass of Kombucha and cups of milky tea – only, sometimes I do not put the tea in so then it is watery-milk aka ‘silver-tea’ – apparently). The watery-milk/tea may be ‘cheating’ but the Venerable Bede, writing in the late 600s – early 700s* records an exceedingly pious bishop as fasting ‘eating only a small piece of bread rarely and drinking watered milk’, so there is a precedent – even if I am only doing 16 – 18 hours – and he was doing the whole six weeks of Lent. [*I’ve been reading Bede’s ‘The Ecclesiastical History of the English People’ as part of my research for Dominica – my first historical novel set in late AD600 early AD700 Cornwall]

Which brings me neatly to Lent. This year I thought I might try to fast once a week – but for forty hours at a time. (You can see my thinking?) My plan was to begin the same way – 6pm, replete from a good Sunday fill-up – and keep going until Tuesday 10am. However, quite often I carried it on to noon – making it a 42 hour fast.

The first thing I learnt from a 40 hour fast was that it wasn’t as hard as I thought it would be!

The worst time, each time, was around 3pm on the Monday. After that was beaten – it returned to being easy. I have to say – I had pre-prepared meals for my OH – so I only had to heat them through and present them to him. I’m not sure it would have been so easy if I was preparing and cooking each time when I wasn’t eating – I love raw veg so much I’m sure I would have snacked a piece or two!

The second thing I learnt from a 40 hour fast was that sometimes when we are ‘peckish’ we really are not hungry – we are THIRSTY! 

Oh yes, there were hunger pangs – but generally a cup of hot watered milk and they went away – or, when the weather was hot, just a glass of water and that would do. It is a fact that – when we feel hungry we are often actually thirsty – but our brain is really not very good at telling the difference and telling us what we actually need.

The third thing I learnt from a 40 hour fast was that my mind seemed far more focussed – I got stuff done that I’d been procrastinating over for ages.

To begin with I thought it was because I wasn’t having to prepare and cook on the Monday – which gave me more time … (as I’d made a cook-chill roast for the OH at the same time as the Sunday dinner and opted to do him a kipper and grilled tomatoes at tea-time – which isn’t my favourite anyway) BUT there was more to it than that – when I set to a task I just got it done quicker – whether working on the computer or weeding the garden.

The fourth thing I learnt from a 40 hour fast was that it altered my sensing of the food in my mouth … and my speed of eating.

My dear OH eats fast! He always has. He likes to eat his food while it is still piping hot. No, really, you cannot imagine how hot food still is when he can happily eat it – I’m still blowing on a forkful to get it cool enough to put in. However, over the forty plus years we have been married I have become faster at eating too – sort of sympathetic speed-eating
After the second forty-hour fast I found I just couldn’t eat that speedily any more. The flavours and textures of the food were almost a little overwhelming – they needed savouring, each mouthful slowly and separately.

The fifth thing I learnt from a 40 hour fast was that I had more energy!?!?

WHAT – no food – but more energy?! I know. Weird – and totally unexpected! I, like others I have spoken to, thought that I would naturally feel lacklustre and sluggish, but the opposite was true! I suddenly found myself thinking – ‘Yes, I will walk there!’ (where-ever there was) rather than hop in the car. (I’m only talking short distances here – a couple of miles round trip generally) And then, when the OH was away for a while, I found that taking the dog for good-length walks was a pleasure – rather than a chore! Same goes for tackling some of the heavier garden jobs I’d been putting off.

The sixth thing I learnt from a 40 hour fast was that it had re-educated my appetite.

I suddenly noticed that I was getting proper ‘FULL!’ signals … and they were easy to recognise. I began listening and acting on them – so, for instance, my post Lunch yoghurt – became my tea (with a few added nuts and fresh berries) if my lunch had filled me up. Some meals I would normally have eaten, were just too much – so I was careful not to overload my plate next time. (can’t abide food waste – better not to put it on the plate)

I found these last two changes odd, and have since looked for a reason. According to Dr. Jason Fung, talking about 42 hour fasts – “There’s a very good reason for this decrease in appetite. As you start to break the insulin resistance cycle, insulin levels start to decrease. Since insulin is the major regulator of the body set weight (BSW) your body now ‘wants’ to go lower. In response, hunger is suppressed and Total Energy Expenditure is maintained. So – appetite goes down and TEE stays same or goes up. “

Lent is over … and I have resumed my weekly 16 – 18 hour fasts – but the legacy of the 40 hour fasts persists. Lowered appetite – heightened focus and energy – and, incidentally (as this wasn’t the object of the original exercise) noticeable weight-loss, even with the resurgence of my regular weights exercises to keep my muscle mass up – that is – losing weight even with putting on increased muscle weight!

I was careful to check that over the eating days – say over three eating days, my nutritional balance was right. That is, as long-time readers may recall, a low-carb balanced way of eating that I have tried to follow since the mid 1970s. It’s an omnivorous diet with nothing banned: meat, eggs, plenty of veg, nuts, home-made plain yoghurt, cheeses and a moderate amount of fruit – but very little carbohydrate-rich foods – like potatoes, pasta, bread, rice, sugary stuff etc. The only difference in my eating pattern, since back then, is that for the last few years I’ve try to cut out gluten as much as I can following the healthy gut-biome protocols (see here)

Which, also incidentally, is a way of eating Dr Fung agrees with. [remember, I’ve only just found what he says trying to work out why the energy levels and appetite seemed to act counter-intuitively]
Low-carb, whether very low to take you into a ketogenic stage, or moderately low (as I generally do) combined with fasting works to positively help your body lose stored fats. Remember, low-carb is also often fairly high in calories as good fats and proteins replace the carbohydrate elements – and Dr Fung continues the quote above by adding :-
“Note that standard ‘Caloric Reduction as Primary’ {cutting your calorie intake)} strategies produce the opposite effect – appetite goes up and TEE goes down.”  

Yes, well, we met this problem way back when I was trying to work out what to do about the menopausal weight that had crept on (see here) … the answer to that wasn’t cutting calories (as many women are advised to do) but to build muscle – because if you cut calories drastically you end up in a viscous cycle whereby, lack of calories means your body takes the extra energy from your muscles first – before your fat – meaning it would make it even harder to lose weight – as to lose weight you need muscle-mass to burn it for you!

{{{ NOTE: People who should NOT fast include those who are underweight or have eating disorders like anorexia, women who are pregnant or breastfeeding, and people under the age of 18. People on medication for conditions such as diabetes, should only fast with the consent of their doctors }}}

So, with that very important warning in place – I’ll leave you with the thought that maybe our bodies were designed to eat when food was plentiful – and ‘fast’ in between times. A hunter-gatherer lifestyle would create just that scenario on a regular basis.

Anyone here into fasting?
Noticed any unusual side-effects you didn’t expect?
Do share – you know I love to hear from you!

best – Ann

ps If you are reading this on email and would like to comment just click onto the title and it will take you to the actual blog – so you can comment there
If it is the first time you have written a comment don’t worry if it doesn’t appear immediately, your first comment has to be verified (to keep the spam-bots out) and I do this personally – so I am sure to see your comment – thanks for reading – Ann

Remember – reviews of books are a great way to say ‘thank you’ to an author if you like what they write,
  Thank You


2 thoughts on “SIX things I have Learnt from forty-hour Fasting

  1. I’m a great fan of intermittent fasting (IF) and have often gone for a week at a time eating just one meal a day and it is nowhere near as difficult as it might sound, as you have found. I’m also a fan of Dr Jason Fung, and he explains that back in the hunter-gather era, if you got sluggish and had no energy when you fasted, then you wouldn’t have the energy to go and hunt or gather! Makes sense, eh? And actually your body is still eating, it’s “eating” your stored bodyfat, that’s what it’s for. If that didn’t happen, we, as a species, would have died out long ago, yet here we are…

    Very interesting blog post, Ann, and I have to say that eating OMAD also means less food to buy, less time spent cooking and preparing, less washing up, less wastage, and more time and money to spend on other things, new things, even hunting and gathering 🙂

    • Hi Christine,
      What a great comment to start this one off! One Meal A Day can really save you all that time and effort too, but I wonder if doing it every day stops it being intermittent fasting, as it is a regular daily pattern?? Not really looked into that. (Note to self * look that up)
      (Dr Fung seems to put his obese type 2 diabetes patients in to a one on, one off, fasting / eating programme, or longer fasts, but only twice a week)
      I guess we all need to do a bit more of the hunting and gathering for it to work perfectly 😉

Leave a Comment

Enjoyed this blog? Please share :)