Four-Day Fast

When you tell people you haven’t eaten anything solid for four days, they usually react in one of three ways: 1) Disbelief i.e. you’re lying your ass off, 2) Concern i.e. they want to grab you a chair because they are scared you might pass out at any given moment, or 3) Bewilderment - Why would you do that yourself?

I didn’t eat for four days. And for those folks in camp #3, first, let me lay out why I wanted to deprive myself of food for four days.

The Why

Challenging the Status Quo

I am in my mid-30s and for all my life I have consumed approximately three meals a day plus snacks. This adds up to approximately 35,000 meals and probably 70,000 small snacks! Never in my thirty plus years did I question if I really needed to eat at such a regular internal. Crazy. What would happen if I failed to eat for a day? Lightheadedness? How about four days? Death?

Health Benefits of Not Eating

There are been a lot of positive research both on caloric restriction and fasting. For example, how fasting can starve cancer cells. If fasting is something that can lead to health benefits and it is not too taxing on the quality of life, maybe it is something that I would want to pursue at regular intervals throughout life.

Mental Clarity

Steve Jobs was a regular faster. According to his memoir, he did this for feelings of ecstasy and mental clarity. Gandhi was also a faster for similar reasons. And countless other great humans. Maybe they were on to something.

Other Physiological Benefits - Ketones vs. Glucose

There are two main sources of fuel for the human body: ketones (derived from fat) and glucose (derived from carbohydrates). Glucose is the preferred energy source for the body and if it is available (which is usually always the case in a non-fasted state), it will be used and ketones will not. In a fasted state, the glucose store is reduced and the body is forced to break down fat and switch to using ketones as the energy source. In short, a decrease in body fat is guaranteed while doing an extended fast.

When levels of ketones in the blood rise above 0.5 mM/dL, it is known as ketosis. Interestingly, inducing a ketotic state (ketosis) is also used for [treatment of seizures from eplilepsy]. In addition to fasting, it can also be induced by eating a high-fat, moderate protein, extremely minimal carbohydrate diet. It is questionable whether being in ketongenic state, whether through fasting or diet, is healthy in the long run. There are possible side-effects like kidney stones.

What It Was Like - 4-Day Fasting Journal


Prior to embarking on my fasting experiment, I got things in order. First, I made a beef bone broth. A bone broth is a nutrient-dense broth that is beneficial to consume during fasting to ensure electrolytes e.g. sodium/potassium, and other micro-nutrient levels stay in balance during fasting. Secondly, I purchased some exogenous ketones (I chose KetoForce). It has been suggested that when transiting from using glucose to ketones (around day two of the fast) that the body breaks down muscle. Exogenous ketones are supposed to help with this transition from glucose to ketone burning. I also wanted to continue weight training and cardio (primarily running) during my fast so I decided to take intra-workout amino acids. Lastly, I purchased a Xtra Precision Monitor because I wanted to measure my glucose and ketone blood levels throughout the fast.

For the body fat testing, I used the electrical impedance method with the Withings Body - Body Composition Scale. This is not the most accurate way of measuring body fat percentage, but I didn’t feel like shelling out a couple of hundred dollars for DEXA Scans or Bod Pod sessions.

Day One - Baseline

Weight: 183.9; BF%: 20.9%; Glucose-Level: 85 mg/L; Ketone-Level 0.1 mM/dL

Started fasting after lunch on Saturday, March 4th. The last meal I would eat for the next four days was a bowl of turkey chili and a side salad.

7 AM - Woke up and had coffee with a bit of coconut milk.

12 PM - Lifted Chest and Back. Consumed 5g BCAA intra-workout. Even though I hadn’t eaten for ~24 hours at this point, my strength was normal. Also, my workout was not affected by hunger.

3 PM - In an effort to ease the transition to ketosis, I took the first dose of exogenous ketones (KetoForce). The bottle warns that it is pH-basic and suggests mixing with an acidic beverage. I decided to mix the 15 mL serving size with lemon water.

5:30 PM - Had my first cup of bone broth. Was pleasantly surprised by its robust taste. Felt good to get a little flavor in my day.

9 PM - Took ZMA and had a cup of ginger-turmeric herbal tea. Went to bed.

Overall, the first full day of the fast went well. I had the urge to eat later in the day. I believe this was more from habit and/or boredom than hunger.

Day Two - A Long Day Into Ketosis

Glucose-Level: 82 mg/L; Ketone-Level 0.9 mM/dL

The morning of the second day of the fast, I woke up at 3:40 AM (!) and couldn’t fall back asleep. This would be a theme throughout the fast– my sleep schedule would be affected. I figured since I was up I would get after it. I had two workouts scheduled…

4 AM - Had 2 cups of coffee w/ a bit of coconut milk. Meditated for 10 minutes.

4:30 AM - Did some work. Hunger level was low and did not affect focus.

5:30 AM - Took pre-workout exogenous ketones.

6 AM - Weight trained legs and core– leg presses, lunges, hanging leg raises, etc. Felt energetic (might be 2 cups of coffee before). Forgot intra-workout amino acids:(

7:15 AM - Took post workout amino acids.

8-9AM - 2 cups of black coffee at work. Had to do it because I was really feeling the effects of waking up at 3 AM.

10 AM - Started to notice the hunger a bit more. This is my typical snack time which might have something to do with it.

4:30 PM - Cup of Bone Broth. This is like an oasis in the desert to the faster.

5:30 PM - Went to MX4 (high-intensity interval training) class. Remembered to bring my amino acids this time:)

6:30 PM - Feeling the hunger start to sink in. I really wanted to stop at Panera for a bowl of chili. Instead went straight home and consumed another cup of bone broth.

8 PM - Had a cup of ginger-turmeric and kava herbal tea.

8:30 PM - Took ZMA and went to bed.

Day Three - The End In Sight

Glucose-Level: 66 mg/L; Ketone-Level 1.7 mM/dL

I didn’t sleep well again. I think part of the reason was due to thunderstorms, but I also think there is some physiological reason due to fasting… Possibly a slower metabolism rate for caffeine?

5:30 AM - Wake up. Had a cup of coffee. Meditated.

7 AM - Had a bit of an upset stomach. Possibly due to coffee on an empty stomach. Decided to skip the gym.

8-10AM - 2 cups of coffee at work.

12 PM - Had a feast for lunch– 2 cups of bone broth.

1 PM - Noting that I had some sugar free gum. Not sure if this is ideal while on a fast.

5 PM - Cup o’ bone broth.

6 PM - Walked on the treadmill since I missed morning workout.

8 PM - Another early bedtime.

Day Four - Breaking the Fast

Weight: 177.2; BF%: 19.0%; Glucose-Level: 61 mg/L; Ketone-Level 4.5 mM/dL

4.5 mM/dL Ketones Measurement

On day four, I slept a bit better– ended up sleeping in until 7 AM and skipping the gym again. At this point, I was well into ketosis at 4.5 mM/dL. Broke the fast by eating a Starbuck’s Sausage, Cheddar & Egg Breakfast Sandwich at 8:15 AM.

End Results

Well, I lost 6.7 pounds and 1.9% body fat during my 4-day fast. Not too shabby. Beyond the physical results, I learned a whole lot.


The biggest thing that this fast has taught me is just how much I eat out of habit or boredom instead of actual hunger. I was never extremely hunger during the fast– at most it was a dull pain.

The effect on sleep also interested me. After reading a lot on fasting, that doesn’t seem too common. This is an area I would like to explore more.

If I were to fast again, I probably would pay for a more accurate body composition test. It would be interesting to see if exogenous ketones/amino acids helped in preventing the breakdown of muscle and the transition into ketosis. Based on this experience, I am still not 100% bought on the idea of exogenous ketones.

Lastly, I would avoid all fake sugar, including gum. I thought of my fast as somewhat of a detox/cleanse. Although fake sugar has zero calories, it still must have some physiological effect on the body.

Next up, a 7-day fast.

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