I didn't eat for five days. Here's what happened.....

 

For five full days, I didn’t eat a single piece of food; I consumed only water, coffee, and electrolytes. I don’t do intermittent fasting, nor have I ever done a 24-hour fast. Here’s the story.

Every year, I do a “Misogi.” A misogi is a challenge that pushes the limits of what you believe is possible. It’s a challenge that pushes the edge of your potential. It’s hard. It’s a grind. It’s pure suffering. But you ultimately come out at the end a stronger, more resilient person.

I’ve been practicing misogi for years. I went on a 10-day silent meditation retreat. I completed Month to Master where I mastered 12 skills in 12 months. I also biked 500 miles from SF to LA. I started my own business.

The Call

In 2017, I read Nat Eliason’s blog post on 5-day water fasting. Not eating for one day was unfathomable, so not eating for five days felt completely impossible. But that blog post planted the idea and sat inside my brain, taking years to eventually sprout.

Fast forward to 2024, I began dating my current girlfriend. She was the first person to not writhe in horror when I told her about my misogi challenges. In fact, she attempted to do a 7-day juice fast before, but had to break it at 5 days since she began getting cold shivers.

She was the final push I needed, and we both decided to take on this challenge together. I’d do a five-day water fast, and she'd do a five-day juice cleanse. 

The Rules

The rules of a five-day water fast are simple: don’t eat anything for 120 hours. I can only consume zero-calorie liquids (usually water). Some practitioners don’t recommend consuming black coffee. Some say it’s fine. I’m a coffee addict and needed to be productive at work, so I allowed myself to drink black coffee. My girlfriend only drank only home-squeezed juices.

Aightt, before we dive into this, this is the part where I tell you that I’m not a healthcare professional. If you want to do this, do your own research and if you have doubts, talk to a professional.

The Benefits

Fasting has a ton of health benefits.

Of course, there are a lot of studies showing fasting could also harm you such as increased inflammation and higher cardiovascular death risk for some specific types of people, so it’s important to also think about your personal situation.

Preparation

Fasting literature recommends following a ketogenic diet five to seven days before the fast. This way, your body gets used to fewer carbs, preventing a blood glucose crash. 

Like the good student I am, I did none of that and ate ramen with a few friends for my final meal. But I did purchase a blood prick, glucose/ketone testing monitor: 

When doing a water fast, you want to measure two things: blood glucose and ketone levels. The blood glucose measurement is important for making sure your blood sugar doesn’t drop too low, as you could pass out. Diabetics are typically at risk. The best way to measure this is through a Continuous Glucose Monitor (CGM) as you’d get constant readings

The purpose of ketone testing is to monitor how deep into ketosis you are. When you’re eating carbs, your body will first use the carbs you ate for energy, before using fat stores. But during a fast, you’re not eating, so you’re body will directly use fat stores to energize your body. This state is called “Ketosis.”

Day 1

When I woke up on Day 1, I felt…….. normal. My girlfriend was on a work trip, so we’d have to start our fast separately. I decided to work from home the rest of the week since my office would have too many tempting snacks. Day 1 figured to be the easiest day. 

My ketone levels were at 0.1 mmol/L. I need at least 0.5 mmol/L for mild ketosis and 2.0 mmol/Lto be firmly in ketosis. My glucose level was 69mg/dL, which is a bit low, but I felt fine. Ideal range is 70 to 120mg/dL. I made a cup of black coffee, drank a cup of electrolyte water, and began grinding away at work.

By 11 to 12 noon, I started feeling pangs of hunger in my stomach. I drank a bit of water, ignored the hunger pangs, and continued grinding on work.

My girlfriend was arriving home from a work trip at Penn Station at around 4pm. So at 4pm, I walked to the train station to pick her up. I noticed myself feeling lightheaded and the stimulation from the NYC streets was overwhelming. The combination of the gridlocked, Penn Station traffic, and the aroma of the halal street carts, overwhelmed my senses. Breathe. I felt like I was smelling in high definition.

After getting home, I worked for a few more hours. For dinner, I had a five-course serving of water and electrolytes. The nice part was that I had another two hours of free time since I didn’t need to spend the time eating. By this point, electrolytes were the only thing stimulating my taste buds, so I loved drinking electrolyte water. 

When you’re fasting, your liver begins secreting more sodium as it works to supply glucose to your body. To make the fast easier, supplementing with zero-calorie electrolytes helps replenish sodium deficiency.

I noticed that despite hunger pangs, I was in a really good flow state the whole day. I didn’t have my usual post-lunch carb crash, so my focus never waned in the afternoon. I felt clear-headed and a slight pinch of euphoria. But it’s only day one?

I tested my ketone levels: 0.6 mmol/L. I was in “mild” ketosis. Didn’t expect to reach ketosis so fast. My guess, it was because I worked a lot and had burned through all my energy stores. 

Day 2

When I woke up on Day 2, I didn’t feel too hungry. I walked gingerly out of bed feeling OK, but whenever I picked something up or did something remotely strenuous, I’d feel lightheaded. The cure was to drink electrolyte water. I felt some brain fog, but the coffee washed it all away.

My girlfriend and I meditated and then we started work. Ketone Level: 0.8 mmol/L. I had an important presentation to give on Friday, so I was locked in. I felt locked in. The combination of an urgent deadline with ketosis easily tipped me into a flow state. I felt clear-headed, productive with a twinge of euphoria.

The hours raced by. I felt like I was playing life on 1.5X speed. I crushed through my analysis and by the end of the day, I actually didn’t feel hungry. I felt amazing. My girlfriend and I decided to take a night walk, which caused me to feel lightheaded again. Chugged another electrolyte and then felt fine.

Before sleeping, I took another ketone reading: 2.5 mmol/L. Holy shit, I’m in ketosis. It made sense since I was feeling so good. My girlfriend was reading a 0.6 mL/L which meant she was in baby ketosis. But overall, I reached ketosis pretty quickly and I was feeling incredible. 

Day 3

I woke up on Day 3 feeling like complete ass. My lips felt like shriveled grapes. My dry taste buds on my tongue felt like sandpaper. I noticed that my stomach kept growling all night. My digestive tract was doing a ton of work. Oh, and I no longer needed to shit on Day 2.

As I crawled out of bed, working a full day felt insurmountable. I hobbled to the kitchen and poured myself a cup of water. I chugged the water like a lost desert scavenger. Like magic, I instantly felt like a new person. The water revitalized every muscle in my body. I guess I was dehydrated but found it crazy how much of a difference a single glass made.

I tested my ketone level again 3.1mmol/L. A range of 3.0 to 5.0 meant you were in deep ketosis. It’s still safe but you’re body is an accelerated fat burning state. I drank another coffee and was ready to crush the day.

I whipped open my laptop and fell back into a flow state. Though I felt ass in the morning, I again felt extremely focused and locked in for work. If I didn’t feel like ass, my mind felt clear. We crushed the presentation. We had expected our stakeholders to push back and request more work, but they agreed to our proposal, which meant we hit our Q4 goal two months early.

Mixing ketosis with the euphoria of accomplishment made me feel on top of the world. I spent the rest of the night chilling, watching TV, and giggling to myself about my win at work. 

Each time I felt shitty, I downed another electrolyte drink. But I was getting sick of drinking these damn electrolytes. And gradually through the night, the stomache rumbles grew louder and louder. WTF

Probably TMI but I do it for the story. I went to the bathroom and needed to shit? It was liquid-y, but I realized that I had been drinking too many electrolytes. My body was rejecting it and it was coming out the other way. Oops.

Day 4

I woke up in the middle of the night feeling even more ass than Day 3. This time, I had a glass of water on the nightstand, so I chugged it and immediately felt better. 

When I woke up in the morning, I felt the worst out of all the days. My muscles felt drained of energy and I felt lightheaded. And since this was a Saturday, I didn’t have work. I took another ketosis reading: 2.6 mL/L. Work was great for distracting my mind from hunger but it also required me to expend energy, allowing more ketones to be created. When I didn’t have work, it was easy for my mind to revert to feeling hungry. 

The takeaway, is during a fast, it’s important to engage your mind in something. For the past few days, whenever I felt hungry, I redirected my focus to work. But with nothing to engage my mind, I missed the sensation of flavors like a child misses his mommy.

I began counting down the hours until we could eat: 36 hours. To engage our minds, my girlfriend and I began planning our November trip to Mexico. We furiously clicked and typed away, scurrying through hotels. Anything to avoid the thought of hunger. Two hours flew by. We hung out on the rooftop of our building, basking in the sun, just talking about life.

Oh look, it’s time for lunch again. Time to have… more water. 

At night, we made plans to watch “The Conclave” with friends. Mentally, it felt like a massive effort to get out of the house, but we had to do something to occupy our minds.

At around 6pm, we put on our coats and stepped out of our home and gingerly walked to the subway. We scurried through the human traffic jam aka Time Square. 

We stepped into the theatre, where a wave of warm, buttery popcorn flavors flowed into nostrils. Drops of saliva flowed down our tongue’s but we quickly snapped out of it. During the fast, we started making a list of all the food we wanted to eat after the fast. Making a list for myself actually made me less hungry. I jotted down a mental note to eat buttery popcorn.

When our friends came, I felt a surge of energy. I don’t know whether it was distraction or if it was interacting with other humans, but it gave us energy. I focused on the conversations, not on our hunger. We ignored the popcorn aroma and watched the movie in peace.

Day 5

Day 5. 12 hours left. Ketone Level: 5.1 mmol/L. I’ve surpassed “deep ketosis.” According to ChatGPT, “it may be a sign my body is in unusual metabolic stress.” But apparently, it’s still safe. Above 8 you put yourself at risk of ketoacidosis. This is when your body is creating too many ketones to where your blood becomes acidic.

 
 



Day 4 was our toughest day. Day 5 was a celebration. We felt like we were about to hit the finish line. At this level of ketosis, apparently you shouldn’t have as much of an appetite, but i was so damn excited to eat.

I drank another glass of water. It was also the day of the NYC marathon. I don’t usually get FOMO, but I definitely had FOMO. I wanted to be out there to celebrate my friends' running and be a part of the celebration in the city. But alas, I need to finish this. I opened up my laptop to track my friends times. 8 hours left.

Since it was football Sunday, the fear of losing in fantasy football completely distracted me from my hunger. 5 hours left. I kept refreshing the Sleeper fantasy football app. Touchdown Chuba Hubbard. Touchdown Terry McLaurin. Let’s gooo!!!!!

My girlfriend flipped on cooking shows and surprisingly, watching cooking shows didn’t bother us. 3 hours left. 

We actually felt less hungry than Day 4. And as the clock ticked away, it finally struck 6pm: time to eat. 

How to Refeed

Refeeding is the process of steadily introducing food back to your body. The key is to have easily digestible foods that don’t spike your blood sugar. Typically, people will break their fast with bone broth, then move to unsaturated fats and then protein. Supposed to avoid vegetables for a few hours as it’s more difficult to digest and avoid carbohydrates (especially sugar) as it’s going to spike blood sugar.

I’m a good boy, I followed the rules right? Nope. We ordered chicken soup but the congee came first, so we had congee for our first bite. Immediately after having a few slurps of congee, the carbs spiked our blood sugar. It felt as if we were on a natural “high.” Like an overworked computer, our bodies were on overdrive. We needed to give our bodies a break every few sips.

 

Photo of us eating our first bite of congee!

 

When we scanned through the menu, we couldn’t resist. We ordered roast duck and fried shrimp. The roast duck bite was one of the best bites I ever had. Roast duck is fatty, high in protein, and has a lower glycemic index, so we felt like we could keep eating it without overworking our bodies and it was significantly more flavorful than the other dishes we had.

After eating, we felt full. I no longer felt light headed, hungry. That night, I no longer woke up in the middle of the night dehydrated. My sleep went back to normal. Everything went back to normal…..

Reflection

I get the same question: did you feel lasting health benefits from the fast? Many people who’ve done this say they felt incredible.I felt incredible during ketosis.  I lost 11 pounds, but I felt the same as I did before the fast.

But mentally, I felt unbreakable. The health benefits were nice, but the biggest change for me was the impact on my confidence.

Growing up, many of us dealt with feeling “not good enough.” I definitely did. On my first day at USC, I was surrounded by peers who scored 2300+ on the SAT, compared to my meager 1860. When I took my first data science class, everyone had degrees in Math, Statistics or Engineering, compared to my business degree. When I first broke into tech, I was surrounded by colleagues with Ivy League or PhD pedigrees. Even now at Netflix, I’m the only Data Scientist in the company, with no Master’s or PhD.

At each stage of my life, there was a reason to feel like I wasn’t good enough, that I was an imposter, that I didn’t belong. But the counterintuitive solution is to run toward the challenge, not away from it. While sure, there were health benefits from the fast, more importantly, it further reinforced the belief that I could take on any challenge in front of me. 

Seven years ago, not eating for five days was completely outside my reality. It’s now an infinity stone, tattooed into my arm, that I keep for life. Now the question is, what’s next?