A diary of a one week fast

Photo by VD Photography on Unsplash


My thinking is that a lot of religions have rites requiring fasting about this time of year.  And that when you unpick the word of God stuff, there is some imparted wisdom that has been lost in the message. Food would have been at its most scarce and people most years would have gone days without food, or at least very little, carefully rationed to last.  I’m sure a few clever ones spotted that the normal folk seemed to be a bit healthier than the chiefs who never went hungry and put two and two together.  It is only very recently that scientists have understood the role of autophagy and the important role that plays as the housekeeper of the body’s resources, clearing out knackered cells to reuse the bits to make new ones.

This is naturally done in a small amount daily when the body is confined to either one meal a day, or two meals, no more than six hours apart. This has the name intermittent fasting which I think is wrong. ‘In the wild’ it would be normal eating.  For me, to fast is to deny the body food when it craves it. And simply to feel hunger isn’t itself a sign to eat, but a sign to hunt.

Proper fasting – more than a day minimum starts to trigger body systems.

Growth hormone, ketone production, autophagy which also all increase dramatically over the next 48 hours. After about five days there is very little further upregulation.

So what it is like to undertake a fast of a week. This year is the 2nd year I have tried it. I’ll set it out in a quick diary, compare where I can remember from the year before and summarise my thoughts afterwards.



The Thursday evening before I was due to start I suddenly had the desire to drink orange juice. Wondered why at the time and then woke up the next day with the start of a cold…


Starting weight 18st 3lb

Final meal was at 6pm: a good pound of rump steak with a creamy sauce.


Weight 18st 1lb

Woke up feeling rough.

During the afternoon I had two tiny mouthfuls of chocolate cake.. Impossible to refuse when made by your children.

In the evening we went to watch Lee Hurst: We stayed in our seats during the interval. Which saved a few quid, but as the Stables is a community venue I don’t normally mind paying out for a couple of drinks.


Weight 17st 12lb

Woke up to cold roast lamb sitting on the kitchen worktop – that nearly finished me right there, would have disappeared without a trace in seconds normally.

Had a gym session at lunchtime: No loss of strength yet noticed.

After gym I had a cup of marmite.  This is an extra insurance of salt and b-vitamins.

The evening consisted of 2x double espressos.

No hunger pangs yet.


Weight: 17st 11lb

Started the day with 2x double espressos.

Cold is better, although I’m a touch light headed, so guessing this cold is still around.  Burping but acid reflux hasn’t started.

I notice I’m a lot less thirsty today.

At the gym I go for more explosive movements:  Kettlebells jerk, Trolley push and pull, shoulder press, half one legged squats, assisted pull ups and dips.  Acid reflux is bad before the end of the session.

Afterwards a cup of marmite again.

Felt ill all afternoon after the workout. A lot of trapped air. Still some discomfort right up until bedtime.


Weight: 17st 10 lb very small drop?

Feeling dry in the nose – dehydration?

No Acid reflux today yet.

2 coffees and a cup of tea this morning. But no real thirst again.

No Gym

Lunchtime cup of marmite.


Weight: 17st 8lb

Dry in the nose, light headed, almost hung over – guessing low blood sugar. Blaming it on the cold that hasn’t totally shifted yet.

No acid reflux, no coffees this morning.

No gym.

No marmite at lunchtime. Dropped to see if acid reflux improves.

From the afternoon onwards lots of trapped air.

At home girlfriend has a cheesy, meaty pizza and my stomach says come on just give in and eat!

Finished the night on two espressos which settled the stomach until I fell asleep.


Friday: 17st 6lb

Woke up again a little light headed

Lots of trapped air – very uncomfortable. Looking forward to eating again.

Light gym – strength not noticeably worse, endurance was down a bit but that could have been mental weakness. If I had to dig deep the acid reflux was on my case.

Felt better by the early evening but then got chilled later on.  Was shivering in bed and not at all good.


Saturday: 17st 3lb

Woke up feeling ok but decided like last year I was going to end the fast a few hours early.  Popped over to Tesco’s for bacon, egg etc.  Again as soon as I was moving around I felt light headed.

Broke the fast at 9am.

During the day I was a bit shivery.

Thoughts afterwards

Definitely looked leaner and abs had more definition.  More from water loss than fat loss I would suggest.

Last year I lost a good stone and a half and it was about three weeks before it all went back on. This year it was exactly a stone. Five days later I have weighed myself wondering if I have in fact lost a little more weight. Looks can be so deceiving. Already back to 18st!

Took a good day or two before I felt like my normal self again. Last year I was fine as soon as I had broken the fast.  The only issue last year was acid reflux from about day three which became intolerable towards the end. This year I was ropey and light headed all the way through.  Acid reflux was there but not so bad. I think the coffee and Marmite made it worse.

Having hit the gym despite feeling not the best I can report strength was just about all there, and maybe just a little loss of endurance. Whether or not that was purely down to the fast or being ill I don’t know.

Next year

Next year I will not even start unless I feel well.

Also will come off coffee and try to manage on just water – tea at most. See if that sorts the digestive tract out.

If I start going downhill again next year then I’ll cut the fast to five days max in future years.

So would I recommend it?

Well for a start you save on a week’s food every year!

If healthy you can’t do a lot of damage.

Whether or not it makes a discernible difference to a healthier old age I don’t know. With time there will be measurements to test the theory but at the moment theory is all that it is.

So if it piques your interest give it a go – and if you start to feel unwell then just eat something.

One thing that will help will be being fat adapted. So get used to a very low carb diet beforehand. It will cut out a lot of hunger cravings and sugar crashes, especially at the start.

How often to fast

If you are overweight but healthy you can literally get away with eating once every two days for a few weeks.

Even pushing it to a three day fast one a fortnight won’t hurt short term.

There seems to be little benefit for doing a five day fast more than once or twice a year.

Addendum.  At the time of sending, my weight is still 17st 13lb. So maybe a slight reset?


© Gerry Mandarin 2024