I recently completed a three day fast. Many people asked me why (which is a very reasonable question). So, I thought I’d summarize why I did it, what I’ve learned recently, and how it went down.
Why I fast
I’ve been reading and listening to podcasts about fasting a lot recently. I got really interested in it once I discovered the research about the processes the body kicks off while in a fasted state. From the beginning of our species up until a few hundred years ago, humans fasted regularly, so it makes sense that our bodies adapted to it and can still easily survive it. And I thought, what better time to give your body a kick start than the turn of the new year.
The main benefit I was seeking was starting the process of autophagy, which roughly translates to eating one’s self. At a cellular level, there’s a separate process apoptosis, or programmed cell death. It’s not near as terrifying as it sounds and it quite normal. The sub-cellular comparable process is autophagy. It’s the body’s way getting rid of old, broken down parts of cells. The mechanisms for triggering autophagy were just recently discovered by Yoshinori Ohsumi, which earned him the Nobel Price in Medicine for his troubles. Fasting does this because when your body realizes its not getting any more calories, it starts getting rid of things it doesn’t need and won’t have the energy to sustain. But it’s not just the wild wild west where things just start shutting down – it’s a regulated mechanism to recycle old cell components, destroying old and damaged parts and replacing with new ones. I chose a 3 day water fast because it seemed to be the right balance to gain benefits without losing excess weight.
Autophagy has several benefits that scientists are just starting to examine clinically. It’s strongly believed that the failure to clean up these cells is a leading cause of aging. Two of the most devastating (and terrifying) diseases show massive buildups of old damaged proteins – Alzheimer’s Disease and cancer. So, there are scientists who are trying to verify that autophagy (via fasting) may have the ability to purge these damaged cells before they grow into full-blown tumors.
Additionally, autophagy can help clean up the immune system in much the same way. It finds damaged white blood cells, recycles them, and upon refeeding, generates shiny new white blood cells. So, if there’s something I can do that clean up any pre-cancerous cells and regenerate a new immune system, I figured it was worth a try.
While I wasn’t interested in the weight loss aspect of fasting (in fact I was concerned about it), it is a really great way to quickly get into ketosis and really start burning fat. And aside from weight loss, ketosis (and the ketogenic diet) has a host of other benefits.
How I fast
I put together a plan, bought my extremely boring supplies, and had my last meal. It went like this: Eat Thursday dinner, and not consume any more calories (technically I had ~60 every day, will explain) until Sunday dinner. To help with the mental aspect of fasting, I still had “meals” every day, which consisted of:
Breakfast – black coffee with 2 TSPs of coconut oil (where the 60 calories come from). The caffeine and pure fat of the coconut oil help start off the day with an energy boost. If you can deal with a film similar to gasoline floating atop your morning joe, give it a shot. Fasting purists argue it’s not fasting if you consume calories, but since it’s zero carb, zero protein (the two things that may inhibit autophagy), I was fine with it. If you were fasting for the weight loss benefits, you might try skipping that, as it does contribute calories that would otherwise be generated from stored fat.
Lunch – la Croix with 1 TBSP Apple Cider Vinegar. The carbonation seems to help suppress appetite a bit, and the ACV helps regulate blood sugar and gives you a little flavor outside of water. Lastly, if you add the ACV like Emeril Lagasse adds spices, it’s almost like you’re cooking. BAM!
Dinner – 8 oz of warm salt water. This is surprisingly delicious when you haven’t had any sort of food all day, and sodium is the most important mineral to replace when you aren’t eating. Like chicken broth. Without the chicken.
And then I’d drink water as needed throughout the day. I tried not to overdrink as I didn’t want to unnecessarily flush sodium from the body.
How to Track Fasting - The Zero App
This simple (and free) app has been really helpful in my fasting journey. Aside from a timer that will keep track of when fasts began and how long you have til you reach your goal, they constantly post new research and information about fasting, so you can always stay up-to-date. So download the app and give it a try!
How fasting felt
I went in hearing stories all over the board from other random internet people (my main source for all important medical information). So, I decided to just do it and see how it felt.
The hunger actually wasn’t that bad. Don’t get me wrong, I was hungry, but the feeling of hunger plateaued around dinner time of day 1, and never really got worse. And after you’re in a constant state of hunger for a while, you kind of grow used to it.
Energy level was ok. It is suggested that on the first morning, you go out for a long, but casual walk to burn through the rest of your glycogen stores and get your body into fat burning mode (and off carb dependence). It was raining so I just went and walked around Wal-Mart for a while. Great way to distract yourself too. On the last day I started to feel a little tired, but that may have just been me sad and missing my food. Many people say by day 3, they actually have extra energy and brain clarity (likely from being in ketosis) but I didn’t experience that at all.
By far the hardest challenge of all was psychological. You really don’t realize just how much our lives revolve around eating and drinking. Roommates cooking dinner – I’m heading to my room. Football’s on TV, I want a beer. Hell, I thought Uber driving would be a great way to distract myself, and then I pick people up from the local Italian joint, along with their leftovers, and they proceed to tell me how good their manicotti was. Thanks, Gretchen.
On the positive side, I was quite productive. Think of all the time you spend either eating, shopping for food, preparing food, and eliminating food (sorry it’s true). And sitting around watching a ton of TV (where you could possibly see a Taco Bell commercial) wasn’t helpful either. Alternatively, you knock plenty of stuff off the to-do list.
And finally there is quite a sense of accomplishment once it’s over. It’s nice to know that if I ever needed to go without food, I could without issue. And it goes along with what I try to do regularly, which is intentionally practicing discomfort - so helpful to be prepared when you stumble into the unexpected discomfort instead.
How to Refeed
For a fast of three days, strict refeeding protocol isn’t as important as it is for longer fasts. But I still like to take care with my first meal. I generally will eat a carb-free meal (such as baked fish and sauteed spinach), to continue the benefits of ketosis for one more day. I will also refrain from alcohol for at least one more day, so I don’t give my body anything else to worry about.
More Info
If you’re hungry for more information, this is a very strong presentation by Dr. Jason Fung, a leading expert on fasting and health.
July 2020 Update
I just completed my 4th prolonged fast (or version of it). My current goal is to do a 3 day fast twice per year, until the science is able to more accurately answer the minimum effective dose of fasting. As I continue to get into these fasts, I become more comfortable with the feelings associated with them, and am able to adapt more easily. The hunger really isn’t a problem anymore. I did face some pretty low energy levels this time, so when I start again in Jan 2021, I will add an electrolyte mix to ensure I’m getting the proper sodium and potassium levels…hopefully this will make a difference.
I also tracked my weight lost (and subsequent gain) if anyone’s interested:
Fasting:
7/12 - immediately after last meal - 142.6
7/14 - 10 am (38 hrs) - 138.2
7/15 - 7:30 pm (right before refeeding) - 133.6
So that was a total of 9 pounds (or 6.5% body weight) lost in 3 days. I didn’t perform any body fat % tests to quantify, but a big chunk of that is water weight. When you fast, your insulin levels drop and your body simply retains a lot less water.
Refeeding:
7/17 - 4:40 pm (~2 days of refeeding) - 138.4
7/19 - 12:30 pm (3.5 days of refeeding) - 144.0
I’m actively trying to gain weight so I get pretty agressive with my refeeding, but if you were to transition from fasting into a low-carb or keto type diet, your body should stay in ketosis and continue to burn off fat for energy. A great way to kick-start the weight loss.
January 2021 Update
I completed my 5th round of fasting right after the new year, with small tweaks to my process. I removed the coconut oil from my coffee in the morning, to get at completely zero calories. I didn’t notice any difference (or loss of benefit) so I will continue doing this going forward, to be more of a true fast. The biggest positive was scheduling the fast around my work schedule. Days 2 and 3 became so much easier when I could not expend a ton of energy at my fairly active job. I did have some cramping on Day 2, so I still have work to do with electrolyte supplementation. I will try a product from LMNT next time, in order to get the proper quantity of sodium, magnesium, and potassium, without logging any calories. Until next time :)
Fasting and Gut Health
Another interesting area of study is the impact of fasting on the gut microbiome. There has been some belief that fasting would help restore a more healthy, balanced microbiome, based on the hypothesis that the “bad” bacteria that feasts on carbs and sugars would decrease in quantity without their fuel (calories). I haven’t seen a comprehensive quality study done on this just yet, but this fasting study done in December 2019 showed some promise. The researchers found that “water-only fasting dramatically changed the bacterial community that participants developed more homogenous gut microbiomes during the fasting period” and “microbiome changes due to water-only fasting remained in five subjects even after returning to their normal diet, indicating the resilience of gut microbiome was successfully challenged”. They specifically called out a reduction in fusobacterium, which can cause a number of diseases, including colon cancer.
While this is far from conclusive and more research needs to be done, it adds to the list of potential benefits of long-term water fasting.
Any questions? Let me know, I’d love to talk about it!***
***I’m not a doctor. Discuss with a doctor too.