Yesterday I completed a three day fast- that is, for 72 hours I did not eat anything, but did drink water whenever thirsty.
Before I start, please note that this post does not recommend fasting and you should research personally and consult a Healthcare Professional before fasting.
Fasting is something that has been done for thousands of years. In prehistoric times it was just part of life – feast when you had food, and then fast when there was no food available. It had also been used as a tool for mental clarity or for religious or shamanistic rituals for thousands of years. Some cultures still have ritual fasting, the most well known being the Muslim Ramadan where for a month they fast from dawn to dusk.
There has been writings about fasting and health for over 2000 years. The earliest I am aware of is Hippocrates who recommended refraining from eating for certain conditions. In the early 20th century there was also some interest in fasting, with Arnold Ehret’s book Rational Fasting first being published in 1910.
More recently though it has become popular as “intermittent fasting”, both in the 16:8 format, where you have an 8 hour window for eating and 16 hours where you do not eat, and the 5:2 plan, where you eat normally 5 days a week, and calorie restrict on the other 2 days.
There has also been a lot of research into fasting. Around day two of fasting there is an autophagy process, which is basically a spring clean of the cells in the body, getting rid of anything unneeded or diseased, and somewhere around day four to five there is a release of stem cells, which are the building block cells that can be utilised anywhere in the body. There has been fascinating research around metabolic disorders, fasting as an additive treatment for cancer, as well as autoimmune disorders and for longevity.
There is also evidence around SIBO/SIFO (small intestinal bacterial overgrowth or small intestinal fungal overgrowth) which shows that periods of fasting, and adequate breaks between meals, can make a difference as the gut has a chance to “clean out” when there isn’t food needing to be digested every 2-3 hours.
For those who cannot abstain from food completely, new research has led to a “fasting mimicking diet” which has some of the benefits of fasting without complete abstinence from food.
There are also different types of fasting- juice fasts, water fasts and dry fasts brings the main types. With a juice fast you are unlikely to go into ketosis (fat burning mode) as you will be getting regular glucose through the juice. Water fasts involve drinking only water, and dry fasts involve abstaining from food and water, and for a hard dry fast even avoiding contact with all water including showering.
I have been doing intermittent fasting for a while, first with an aim of moderate weight loss in conjunction with a lower carb diet, and then from a general health perspective. I started with a 16:8 type fast, then upped it to the odd 24 hour fast. I did a two day fast during lockdown, and this was my first three day fast.
I planned this fast, for several days beforehand I knew I was going into it, and the mental preparation was part of this.
I was careful that the meal I ate the night before starting fasting was a higher protein/fat meal, lower carb.
I found the first day not a problem- having done 24 hours fasts before I understood the process and feelings. I drank water when thirsty and it was easy. That evening meal was a bit strange, sitting down with my family while they ate, but not eating. No big deal though.
Similarly the second day only had a couple of blips, when I could smell delicious food. It was fine, I had my water and I did add a fruit tea bag to my water a couple of times for the flavour burst. Sitting down with my family at dinner was again fine.
The third day I found much harder. Thursday and Friday I was at work and reasonably busy. Saturday I was home, hubby was at work, and my children eat ALL THE TIME. While Miss 10 prepared lunch (it smelled amazing) I had to prepare dinner and not snacking while doing so was more challenging.
I broke my fast at dinner on Saturday after 72 hours and it was delicious.
What worked well-
Mental preparation
Working and being busy
Drinking water whenever thirsty or hunger pang
Adding a tea bag to my water when I needed something extra
Having my husband cook dinner for the family on the first two nights
What was more challenging-
Being home and having food there
Smells of food when I was consciously not eating
Cooking dinner on my third day and not snacking
I had postural hypotension- my blood pressure runs low most of the time anyway, but after 48 hours I definitely had to be careful when getting up from sitting
My breath smelled – this is a normal reaction to ketosis, smelling slightly of acetone.
What I learnt-
I eat out of habit. Even on the first two evenings I found myself at the cupboard a couple of times. Because it was habit to go there and eat.
Mind over matter is amazing as I just didn’t feel hungry most of the time.
Next time I am considering getting a glucose and ketone monitor so I can check my levels each day – for science.
If you would like to try fasting a recommend researching first. What the Fast was the first book I read about this, which discusses intermittent fasting, and then I got put more books from the library to read more about it. I also took part in webinars from doctors online and read some studies.
You should not fast if pregnant or breastfeeding. Disclaimer, I am still breastfeeding my 3 year old, but only at night before bed or occasionally if he badly hurts himself.
If you are fasting be sensible about your level of activity. Daily activities are probably fine, high impact or endurance exercise is probably not the best idea.
You also need to seriously consider your diet beforehand- a higher carb diet is likely to make it more challenging as your blood sugar will swing up and down more – as well as what you are breaking your fast with. At the very least your last meal should be something balanced, if not higher in protein and fat than carbohydrate, and satisfying.
If you have any medical conditions or take medication please talk to your GP, Doctor or Healthcare Professional first.
This post does not constitute medical advice but is sharing my experience.
Have you tried fasting? What is your experience?