6. Fasting II: Walking the walk

This article is a day-to-day running commentary.

Being the practical fellow that I am - I decided to perform a quick jump into a state of ketosis and autophagy, raising my human growth hormone and noradrenaline levels in the process and restoring my basal metabolic rate (BMR). As per the previous article, you’d know that the best way to do that is through fasting. Thus, I planned to undergo a long-fast, targeting over 72 hours in order to maximize the effects delineated in my previous write-up.

If at any point, the long-fast had become too difficult, it would have been subsequently terminated and thereafter reverted to a daily 16:8 protocol, consuming a total calorie intake of 2500 kcal/day. However, I planned to put complete faith in my body In order to give it the chance it needs to regenerate itself by placing my trust in mother nature.

Day 0 (23.03.19): PRIOR TO FAST

Here, I decided that the fast will begin on 24.03.19 at 14:30, after a massive high-fat meal which would keep me satiated for some time. I had also identified:

  1. The daily training regimen for the week

  2. The daily supplementation regimen for the week

  3. The methods of monitoring during the week

The Daily Training Regimen

My work days involved 12.5 hour shifts taking up the form of a day duty (07:00 - 19:30) and/or a night duty (19:00 - 07:30). My daily training regimen for the purpose of this write-up involves a morning and an evening workout which could have been any of the following:

  • power training (maximum 3 sessions per week; divided into lower body, pulling exercises and pushing exercises)

  • endurance training (could be anything from walking, to jogging, to sprinting)

  • taekwondo (intensive martial arts training with focus on physicality and technique)

In addition to the training conducted, I was able to cover a minimum of 8, 000 steps per day. All activities were tracked with an apple watch (series 4).

The Daily Supplementation Regimen

I recognized that total absence of nutrients put me at risk of micro-nutrient deficiencies, particularly in relation to electrolytes. For this purpose I planned to supplement myself with the following:

  • Multivitamin

  • Salt Shots (6 g daily)

  • Water (copious amounts)

  • Black coffee (as needed)

The Methods of Monitoring

The strategy I used for monitoring revolved around:

  1. Weight (kg) monitored daily (random time, post urination)

  2. Blood Pressure (mmHg) monitored daily (random time)

  3. Blood Glucose (mmol/L) monitored daily (random time)

  4. Body Fat Percentage (%) monitored daily using a 3-site skinfold caliper test

  5. Chest, Waist and Thigh circumference (cm) monitored daily

To detail the 5th marker, the chest was measured by placing one end of the tape on the fullest part of the bust, wrapped around by passing it under the armpits and around the shoulder blades. The waist was measured by using the tape to circle the waist (as a belt would) at the natural waistline. This was located above the belly button and below the rib cage without sucking in the stomach. The thigh was measured by wrapping the tape measure around the thigh from front to back and then around the front at the fullest part of the thigh, under the buttock.

Day 1 (24.03.19)

Day Summary
As I woke up, I immediately consumed my salt shots/multivitamins. No breakfast. Just headed off to the first taekwondo session of the day where I took part in a 150 minute session of sparring (Apple Watch: 1014 kcal). I got home, washed, changed and headed off to a family lunch where I easily consumed a 1500 kcal meal in one sitting as my final meal before I began my fast (precisely at 14:30). My second workout of the day consisted of a 60 minute walk (Apple Watch: 202 kcal) carried out with no problems or fatigue. At 16:00, I got to have a 2 hour nap in order to prepare for my night shift, where thank God - we weren’t busy. By 22:00, I became aware that my body ceased production of insulin and I still hadn’t been hungry.

Weight (kg)

  • 15:00 - 74.95 kg

Random Blood Pressure (mmHg)

  • 18:00 - 130/82 mmHg

Random Blood Sugar (mmol/L)

  • 21:00 - 3.8 mmol/L

Body Fat Percentage (%)

  • 18:00 - 12.2 %

Chest, Waist and Thigh Circumference (cm)

  • Chest = 97 cm

  • Waist = 78 cm

  • Thigh = 56 cm

Day 2 (25.03.19)

Day Summary
At the turn of the hour at midnight I still hadn’t felt hungry. I became super focused on my work. Primarily - my patients on the ward, then on calculating macros for my nutrition patients. I felt a bit sharper than usual. Without lunch breaks who would have thought how much one could get done? My body had been readily tapping into non carbohydrate sources in order to create glucose. Glucagon was being used. At 14:00, I completed a 30 minute sprinting session (Apple Watch: 393 kcal). No decline in performance noted - be it speed or motivation. No signs of early onset fatigue. When I got home, I did some paperwork, noting some ‘rumbling in my tummy’. Needless to say, I soldiered on to taekwondo Training (19:00). That time, I did feel relatively unmotivated and fatigued. I definitely did not perform optimally. However, I felt that there were some confounding factors at play. Primarily, a lack of sleep and secondly, I had to contend with the muscle fatigue from the previous session. In any case - I endured and finished the 120 minute session (Apple Watch: 500 kcal).

Weight (kg)

  • 15:00 - 73.70 kg

Random Blood Pressure (mmHg)

  • 06:00 - 119/65 mmHg

Random Blood Sugar (mmol/L)

  • 06:00 - 4.8 mmol/L

Body Fat Percentage (%)

  • 18:00 - 10.14 %

Chest, Waist and Thigh Circumference (cm)

  • Chest = 96 cm

  • Waist = 76 cm

  • Thigh = 56 cm

Day 3 (26.03.19)

Day Summary
Woke up at hour 40 of my fast. So now my body has dramatically increased its fat burning capacity. Presumably my human growth hormone levels were at the highest they’d ever been. In addition, autophagy was taking place and my body was categorically eliminating all the excess cellular junk and defunct organelles and/or proteins in order to sustain itself in terms of energy. Taekwondo Training took place at 08:15 (Apple Watch: 500 kcal). That time, I was more energized. I finished the session strongly with enough energy to spare to go out for a short, 20 minute walk (Apple Watch: 105 kcal). When I got home, I felt like a new man. It was a strange sensation - feeling full of energy when logically speaking I had a stomach that was empty for quite some time. I had experienced a sensation of “cold”, however it was not the first time I had felt this way following a reduction in weight and body fat.

By 15:00 (+ 48 hours) the levels of autophagy had reached another milestone. A study conducted by Alirezaei et al (2010), suggested (strongly) that the greatest levels of neuronal autophagy are induced during the 24 - 48 hour fasting window. The cells that were damaged with age, stress and generally - free radicals were being eliminated at an increased rate. They served no real purpose anyway except for the fact that they were just present. Those things could likely trigger inflammatory pathways which contribute to sickness. As per Levy (2018), autophagy is a highly efficient survival mechanism, responsible for recycling damaged proteins and organelles for use elsewhere, regaining the function of over-used intracellular mitochondria, improving cognitive function by encouraging growth of brain and nerve cells, cardiovascular protection from heart cell growth, eliminating intracellular pathogens thereby rejuvenating the immune system and ultimately through the repair of free radical damage - prevents cancer.

In the evening I carried out a resistance workout (chest and triceps focus) with no problems (Apple Watch: 403 kcal) and followed it up with another 30 minute walk (Apple Watch: 170 kcal). It was incredible. I just had bags of energy that I absolutely did not know what to do with. I got home, continued some paperwork… and was even worried I may not be able to get a good nights sleep - which I didn’t.

Weight (kg)

  • 15:00 - 73.30 kg

Random Blood Pressure (mmHg)

  • 18:00 - 128/80 mmHg

Random Blood Sugar (mmol/L)

  • 18:00 - 4.0 mmol/L

Body Fat Percentage (%)

  • 18:00 - 9.31%

Chest, Waist and Thigh Circumference (cm)

  • Chest = 95 cm

  • Waist = 75 cm

  • Thigh = 54 cm

Day 4 (27.03.19)

Day Summary
Did not have a good nights sleep (as anticipated). I still felt like I was somehow full of energy. I would guess this is due to elevated levels of noradrenaline. Woke up at 04:20 and decided to carry on some paperwork before I had to go for a day duty. Incidentally, it was one of the worst days ever. One of those work days where you are understaffed, and everything is categorically going wrong. My mood was slightly disgruntled - but that was quite usual, I guess. In any case, I was happy, because by 14:30, I had crossed over to the 72nd hour of my fast. This was the final milestone where the rate of autophagy was operating at the highest level possible. I guess it was showing on the weighing scale. At this time, I took the liberty of undergoing a urine dipstick test to determine my level of ketosis. The test read that the ketones produced in the urine were at a level greater than 150 mg/dL (over 8.3 mmol/L) indicating high-level ketosis.

The first light workout of the day was a 60 minute walk (Apple Watch: 239 kcal) which I carried out (as per usual) in my break at work. I was joined by my father, who was out-pacing me. That time, I felt tired, and began feeling hungry. I got back to work at 14:00 in no real mood to carry on, however, I did so for the remaining 5.5 hours, where we were in fact - super busy. I had a couple of coffees to keep me going but by the end of the day, I was starving. I most definitely did not have the energy to undergo a training session in the evening. In light of this, I decided to terminate the fast at the 77th hour by consuming a high-fat meal with a carbohydrate content that was well below 10 g (net carbohydrate) in order to try and maintain internal ketosis.

Weight (kg)

  • 1500 - 72.45 kg

Random Blood Pressure (mmHg)

  • 18:00 - 120/80 mmHg

Random Blood Sugar (mmol/L)

  • 18:00 - 4.0 mmol/L

Body Fat Percentage (%)

  • 18:00 - 9.3 %

Chest, Waist and Thigh Circumference (cm)

  • Chest = 95 cm

  • Waist = 74 cm

  • Thigh = 53 cm

Day 5 (28.03.19): POST FAST DAY 1

Day Summary
I felt like a new man. I had fasted for 77 hours, had a good meal and a good nights rest and woke up ready and motivated to begin my work - seeing nutrition clients, training and later - night shift. I re-initiated my usual feeding protocol of a 16:8 intermittent fast, where I consumed nutrient-dense foods from 10:00 - 18:00 in a total of 2500 kcal/day. I now knew how much my body was capable of comfortably undergoing in a time of famine. Over 3 days of total fasting whilst maintaining athlete-level activities with considerable output.

On this day, I completed a light flexibility workout of 15 minutes (stretching based) accompanied by a 45 minute walk (Apple Watch: 200 kcal). Later, I completed a sprint-interval workout which lasted 30 minutes (Apple Watch: 305 kcal). I managed to squeeze in an hour-and-a-half of sleep in order to be able to function properly for my night duty and off I went.

Weight (kg)

  • 0600 - 72.80 kg

Random Blood Pressure (mmHg)

  • 20:00 - 144/64 mmHg

Random Blood Sugar (mmol/L)

  • 20:00 - 4.3 mmol/L

Body Fat Percentage (%)

  • 18:00 - 8.3 %

Chest, Waist and Thigh Circumference (cm)

  • Chest = 96 cm

  • Waist = 74 cm

  • Thigh = 54 cm

Day 6 (29.03.19): POST FAST DAY 2

Day Summary
The day began at midnight as I found myself at work in the middle of a moderate night. During this time, of course, I was in a state of fasting with the 16:8 protocol. I had no trouble with this and after a day of eating, I definitely wasn’t hungry. Following a sleepless night, at 08:30 I performed an intensive resistance workout targeting the legs and core (Apple Watch: 369 kcal). I went out for a nice family lunch at 13:00. Once that was over, I did a light activity which involved a 90 minute walk (Apple Watch: 456 kcal). During my night shift, a random urine test revealed that I was still producing great amounts of ketones in the Urine - which was super! My body was indeed still burning fat.

Weight (kg)

  • 0600 - 71.95 kg

Random Blood Pressure (mmHg)

  • 20:00 - 130/71 mmHg

Random Blood Sugar (mmol/L)

  • 20:00 - 5.8 mmol/L

Body Fat Percentage (%)

  • 18:00 - 8.9%

Chest, Waist and Thigh Circumference (cm)

  • Chest = 95.5 cm

  • Waist = 74 cm

  • Thigh = 55 cm

Day 6 (29.03.19): POST FAST DAY 3 (FINAL)

Day Summary
The day began at midnight, once again finding myself at work. Still undergoing a 16:8 routine as intended. No problems noted. At 08:00, I underwent an intensive taekwondo sparring session (Apple Watch: 625 kcal). My weight was at the lowest it had ever been. By 12:00, the trial was complete and all data had been successfully collected. Conclusions were displayed below.

Weight (kg)

  • 0600 - 71.60 kg

Random Blood Pressure (mmHg)

  • 20:00 - 128/73 mmHg

Random Blood Sugar (mmol/L)

  • 20:00 - 5.0 mmol/L

Body Fat Percentage (%)

  • 18:00 - 9.0%

Chest, Waist and Thigh Circumference (cm)

  • Chest = 95 cm

  • Waist = 74 cm

  • Thigh = 53 cm

Conclusions

Body Weight and Body Fat

The fundamental conclusion of my self-trial is that fasting is a great hack for weight loss. I started out at 74.95 kg and ended up at 72.45 kg after 72 hours of fasting. That was a total reduction of 2.5 kg in precisely 3 days. After re-initiating feeds, 24 hours later, I weighed in at 72.85 kg, which meant that I only technically increased my weight by 0.5 % (on the scale) after starting consuming food again. The weight dscrrased further following a 16:8 daily fast regimen, coming down to 71.60 kg on the final day. This meant that there was a total reduction of 3.35 kg in 1 week with minimal effort from my end.

Following the anthropometric measurements I had taken, there definitely was a marked decrease in overall size. I had a 2 cm decrease in chest circumference, a 4 cm decrease in abdominal circumference and a 1 cm decrease in thigh circumference in 72 hours of fasting. After refeeding, and 24 hours later, I only experienced a 1 cm increase in size of the chest. It is important to also highlight that during my fasting time, the only resistance workout I had undergone was that of ‘pulling exercises’, targeting the chest and triceps particularly. Due to the fast, it is also important to state that my human growth hormone levels were presumably at high levels. All in all, this could possibly contribute to an increase in muscle size of the chest muscles and their accessories. This is a plausible insight but not one which I can confirm. Despite re initiation of a fasting protocol (16:8) the size kept reducing steadily and resisted change only when I performed training which targeted the muscle groups directly.

Blood Pressure

There was a time in my life, at age 23, where I had to take medication for a blood pressure that was, without failure, over 140/90 mmHg. My doctor had recommended an ACE inhibitor for some time, which I had started. I had tried reducing my salt intake to below 3 g/day as per American Heart Association (AHA) guidelines at the time. With time, in 2019, the AHA had updated their guidelines to less than 1.5 g/day of sodium (AHA, 2019) due to their ‘strong stance against hypertension’. This meant that the general population were asked to take in less than a teaspoon of salt - daily. Despite this, I was drinking salt and water straight from the glass, and my blood pressure normalized. Not only that - it became perfect. I was consuming at least 6 g per day of salt. Precisely 4 times greater than the current recommended salt allowance of the AHA.

After searching and searching, I found no studies that clearly delineated any harmful effect salt may or may not have on the effect of human blood pressure. Moreover, during my own fasting trial, I can honestly say that salt shots served:

  • as a means to promote a feeling of satiety, effectively removing any food cravings (particularly from sugar) that I had had at the time

  • as a ‘magical potion’ for energy, in that with every salt shot I consumed, my body was able to function more sharply, and exercise more effectively, even in the absence of food

At age 25 years, my hypertension seemed to resolve itself after adjusting to the diet and lifestyle which I, myself promote. A high intake of salt was crucial for this. Nowadays, it is definitely not an issue that is affecting me in any way.

Blood Sugar

During the trial, my lowest recorded random blood sugar was 3.8 mmol/L and my highest - 5.8 mmol/L. After initiating feeds in the format of a low carbohydrate diet (less than 100 g net carbs per day), i.e. my usual regimen, no real fluctuations were noted, and blood sugar spikes did not ever increase beyond a level of 7.8 mmol/L. Even post prandially.

Personal Thoughts and Feelings

Prior to undergoing this fast, my principle fear was twofold. Primarily - fear of the feeling of hunger as well as the fear of having a reduction in sports performance.

In the context of hunger, I can conclude that it was not a major issue. I did experience a sensation of being ‘peckish’ on the first day, but after going about my daily activities as usual, in fact, even more so - as I substituted my usual feeding times for either work or training, the feeling of hunger subsided. After the first day, I began experiencing surges of energy that sometimes, allowed me to work more sharply or train with better intensity. Why? I suppose this was due to spiked levels of noradrenaline in the body. From what I understand through years of reading, this is the body’s natural response to famine, whereby animals rely on surges in noradrenaline to give them the ‘motivation’ they need to carry on hunting for prey when prey is difficult to find. My body did not now I was creating the famine myself, but it did react in the way I hoped it would. By the final day, my body fat levels were recorded at 9 % - very close to the ‘essential body fat’ levels of the body. Incidentally, I began experiencing extreme hunger. Perhaps if I had a greater body fat content, I would have been able to withstand longer hours of fasting. Stewart and Fleming (1973) detailed upon a gentleman not that much younger than me who withstood a fast of 382 days. However, he weighed 207 kg and was severely obese. I, on the other hand, was not. I would think that an increased feeling of hunger accompanied by tiredness would be related to the hypothesis that the body now had nothing left to give. As a result, I decided to end the fast.

In the context of performance, I did not really note a significant difference. I did experience a decline in performance in 1 taekwondo session but there were several subsequent confounding factors that could have contributed to this (i.e. lack of sleep or fatigue from the previous session). In any case, as far as the 72 hours went, I did not have any problems, and I conducted over 2 hours of training daily. After the 77th hour of fasting, however, I felt a torrid feeling where if I were to undergo a training session, I would have failed. I think it’s important to listen to your body. It’s simple. If you’re not up to it - don't do it; like that you won’t get hurt. The fast was subsequently ended during this time and I rested and recovered with a high-fat meal. Intense training whilst in a fasted state had been carried out for as long as human history dates back to. However, my favorite tales revolve around how Spartans used to train their young in the Agoge - making would-be male soldiers fight and train after having been in the absence of food for days (Chalakoski, 2018).

After undergoing a 77 hour fast, reverting back to a daily 16:8 fasting protocol was easy as pie (I didn’t actually consume pie). I was happily consuming a total daily calorie intake of 2488 kcal per day, enjoying a full feeling of satiety and experienced no hunger issues whatsoever. I began to understand more clearly that eating regularly is actually not good for you, and that mother nature, in her divine wisdom, granted humans the inherent ability to deal with feast or famine. I was happy to thoroughly detox my body and initiate a thorough state of ketosis in the quickest way possible. I now know that if things get busy at work, or if I get stuck in traffic, missing meals may not be such a bad thing after all. It all boils down to two things - discipline and understanding, and now I have both. One important point to hold to heart is that one needs to know when to draw the line between discipline and stupidity. When attempting a fast, you should not starve yourself. Listen to your body. If you’re hungry, eat. That simple. You are not accomplishing anything by starving yourself, only that you may potentially be reducing your basal metabolic rate - and nobody wants that.

Final Result

71.6 kg (9% body fat) following a full fast of over 3 days and 4 days of intermittent fasting without calorie restriction.

71.6 kg (9% body fat) following a full fast of over 3 days and 4 days of intermittent fasting without calorie restriction.

References

Alirezaei, M., Kemball, C., Flynn, C., Wood, M., Whitton, J. & Kiosses, W. (2010). Short-term fasting induces profound neuronal autophagy. Autophagy. 2010 Aug 16; 6(6): 702-710. doi: 10.4161/auto.6.6.2376

American Heart Association. (2019). New Sodium Recommendations Help You Take Back Control of Salt in Your Food. Here are 4 Simple Steps. Healthy for Good. Retrieved from: https://sodiumbreakup.heart.org/new_sodium_recommendations_help_you_take_back_control_of_salt_in_your_food?utm_source=healthy%20for%20good%20sodium%20blog&utm_medium=social&utm_campaign=media%20press%20statement

Chalakoski, M. (2018). Barefoot and starved, spartan boys underwent grueling combat training but were also punished for not answering questions briefly and wittily enough. Retrieved from: https://www.thevintagenews.com/2018/01/02/ancient-spartan-school-3/

Levy, J. (2018). Benefits of Autophagy, Plus How to Induce It. Retrieved from: https://draxe.com/benefits-of-autophagy/

Stewart, W. & Fleming, L. (1973). Features of a successful therapeutic fast of 382 days’ duration. Postgrad Med J. 1973 Mar; (569):203-209