* DISCLAIMER: While I am a registered nurse, you are not a client of mine. I cannot give you advice to treat, diagnose, or prevent any disease. Please consult with your healthcare provider with any health related concerns or plans to fast, change diet or modify .
Impressed by my 2, 3 and 5 day fasts? Don't be. Yes, I have put in the work to get to this point, but its all science, no special talent, I promise. When I first trusted the science behind fasting, I started with a 14 hour fast, and a 10 hour eating window. I ate my usual first-thing-in-the-morning breakfast, a snack, lunch, a snack, and dinner by 6pm. I lost a teeny amount of weight and was a bit frustrated. I did more research and found that each fasting regimen serves a different purpose, and depending on your goals, not every regimen will work for you. After a month or so on a 14/10 regimen, I started a 16/8 regimen, and that 2 hour difference, made a difference. It meant that I would have to be REALLY dedicated to fit all of those meals I was having in a typical day in an 8 hour window, so I often dropped breakfast and opted for coffee in the morning with a light something something, a lunch if I wasn't still full, no snacks because I was full, and dinner. Dropping breakfast and a snack was enough to start seeing changes in the mirror, the scale, and my mind. I did notice, however, that the next day, I didn't feel as energized during that fasting window, and I decided to change my diet. I learned that when you still eat plenty of carbs and fast, your blood sugar is very sensitive to that. You went from eating a lot of carbs in your eating window, to not eating any during your fasting window, and you may feel tired because it cant easily burn fat when you are still training and maintaining a carbohydrate driven metabolism.
The first day that I started that ketogenic diet while I was fasting, I felt normal. This was because I still had plenty of glycogen stores for my body to use. However, by my third day, I began to feel that same old "tired, drained" feeling that led me to keto in the first place. This time, however, it was expected. I wasn't "replenishing" those lost glycogen stores during my eating window, so basically, my glycogen stores were depleted. Once they are depleted, the body needs a little time to start breaking down fat and actually using it for energy (a day or 2, sometimes more!). During that time, you feel like %$#&^%, because your metabolism is interrupted, but very, very briefly. I continued intermittent fasting 16/8, and by day 5, oh my goodness, I felt so good! Why? Because my body was only being fed fat and protein, and up to 25 net carbs, and my body was also burning fat during fasting, sooo, I never interrupted my metabolism. It was always burning and breaking down fat for fuel, whether fasting, or eating.
About a month on 16/8, naturally, my appetite went down. Like, down-down. I would wake up, get my kids ready for school, clean up after them, and next thing you know, tis 11, 12, 1pm, and I just didn't think about food. Since my body had access to calories, aka, body fat, there were hardly any hunger signals that wrings your stomach like a dish rag. For all my body knew, was that it WAS getting calories, it didn't care if it was from a plate of wings, or my belly. I noticed, that my normal, was eating 2 times during this window, which now shrunk to 18 hours fasting, and 6 hours eating. I would eat a big ol' chicken salad, tacos, meat with veggies around 12 noon, and be full until around 5pm, and wrap up my last meal around 6. I was seeing crazy results, but I was even more intrigued by the science.
Recap: Started 14/10, then 16/8, switched to keto when I still felt a little sluggish by eating carbs, and then 18/6 because of the decrease in appetite or hunger signals before noon.
I stuck with my 18/6 regimen for a month or so before I naturally could go a whole day without eating, unless I scheduled it, planned it, remembered it. One or two days a week, I could go all the way until 4pm before I had any desire to eat. Most days were not like this, but it happened weekly. From all of my research that I have done related to fasting, I learned about ketosis, insulin, energy regulating mitochondria, and autophagy.
Ketosis is a metabolic state, in which the absence of carbohydrates as a primary source of fuel, enables the body to run off of fatty acids and ketones, which are fatty acids turned into another form of usable energy by many cells and systems in the body. The fatty acids used for energy can be dietary, aka, what you eat, or it can be the fat that is stored on, and in, your body. But how do we get into the state of ketosis? When you eat carbohydrates, most of it is used for energy, but some is stored in your muscle and liver as well. Over time, your glycogen stores get filled up, and can no longer fit in the muscle or liver, so it gets converted to fat and is stored on the body. Well, in the absence of dietary glycogen from fasting, or much lower carb intake, the liver begins to use up the stored glycogen in the skeleton muscles and the liver. Once the stored glycogen gets used up, there is a cascade of events, mostly involving hormones, that signal the fat cells to release fatty acids. These fatty acids can be used in the body as is, but some get converted to ketones in the liver. The liver then releases the ketones into the blood stream and they are used readily by the body, including the heart and brain!
Since I was eating keto, my body was constantly getting energy from fat. When I fasted... my body was still getting energy from fat. So I did not feel tired, groggy, moody or hungry when I fasted. This enabled me to go even longer without food.
Recap: lowering my carbohydrates allowed by body to burn fat, whether I was eating or not. My hunger went way down, so I naturally began to fast more frequently, and longer.
One day, I decided to go an entire day and not eat until dinner. When dinner came, I had so much energy, I was freaking my family out. My metabolism was on fire! No wonder healthy kids are always moving, the body literally forces you to use up all the available energy you are making during fat burning. I decided to skip dinner that night. I ate the next day. That week, I did complete daily (only water, a pinch of salt, black/plain teas and black coffee) fasts twice and felt great. I was ready to now do this as a lifestyle. I used a method, called alternate day fasting, or, ADF, in which an individual eats on one day, and fasts the next, and repeat. It is a very successful way to fast for those who are trying to lose weight, reverse insulin resistance, treat type 2 diabetes, and induce healing. I recommend anyone who wants to give this a try to read Dr. Krista Varady's book, The Every Other Day Diet, and Dr. Jason Fung's book, The Complete Guide to Fasting. Both of these books teach you about the science behind fasting, ketosis, autophagy, and more. They debunk MANY MANY terrible myths about nutrition, weight loss, and fasting as a therapeutic means for healing and disease prevention.
In a nutshell, we all fast. We eat, go to sleep, and go hours and hours without eating during our sleep. During that sleep, the body is using stored energy to sustain us. Fasting is simply going longer between meals, and using that stored energy to sustain us, we are simply just awake while doing it.
My tools for successful fasting, and fasting lifestyle
Are you ready to embark upon this journey? Great, but wait, there's more. Above is MY experience with fasting, and no two people are alike. Here are some things that I did to ensure a safe and successful fasting journey:
Got a full physical before I began, including labs, lipid profile, and complete any diagnostics that my healthcare provider recommended (neck pain, so, an x-ray). got the clear, but some people, especially those on certain medications, are pregnant, breastfeeding, under 18 or suffering from an eating disorder should not fast. Talk to your healthcare provider first!
I stared slow. Do not get cocky and try and do a 2 day fast on your first run. Your body, metabolism, hydration levels, etc., need time to adjust and build the necessary cellular ability to handle longer fasts.
Never ignore your body. If you feel ill, weak, dizzy, etc.., eat! There is no reason to keep fasting if your body cannot handle it. When I felt funny, I drank broth, and then had some nuts and then a meal an hour later.
I made sure I was drinking plenty, but not too much water. Stay hydrated. 8 glasses a day is plenty. Drink more if you are thirsty.
When you eat, make sure you are eating foods with good nutrients! You are staying replenished.
If fasting more than 24 hours, I would sprinkle a pinch of salt my cup water 2-3 times a day. This helped me stay hydrated.
Calories break a fast. I fasted as clean as possible. If it tastes like calories, such as diet soda, sweet gum, teas with sweet flavorings, your body may respond to as if it calories. It may raise your insulin, which may halt some of the benefits of the fast, such as stopping the fat burning pathways, inducing hunger and cravings.
Be patient. Most people can build up to longer fasts in just a few weeks with patience and great fasting education. It took me roughly 2 months to be able to go an entire day without eating, and another month to start my alternate day fasting lifestyle.