Practical Steps to Start Fasting: The Ultimate Guide for Beginners
New to Fasting? You’re In the Right Place
I just completed a 5 day water fast, and video’d the experience — watch the VLOG here.
Anyway, while discussing my fast with people after the fact (I don’t tell people I’m fasting while I’m fasting, more on that later) I got some pretty wild responses.
To start, most people literally couldn’t wrap their minds around the fact that I didn’t eat for 5 days. I could see them struggling with whether or not they believed me.
Once they reconciled that I had actually fasted many people told me I was crazy or immediately said that can’t be good for me and commenced to lecture me on nutrition, which I handled gracefully I must say.
The open minded few who could move past their doubt began to gush with curiosity. “Why did you do that? Actually, how did you do that?”.
I should have expected resistance and doubt and curiosity. Fasting is extreme for someone new to the practice — it was to me when I first started.
I have been fasting mimicking once per month for the past 9 months — I’ll explain fasting mimicking shortly. I also intermittent fast, which means I only eat from 2:00p to 8:00p each day (18:6). I randomly throw in single day fasts when my body feels like it needs it, and I mentioned that I just completed a 5 day water fast.
Practicing multiple types of fasting has resulted in a fair amount of knowledge on the topic, yet I was still having difficulty explaining it to people who were trying to wrap their mind around why a normal person would ever voluntarily give up food.
This is a summary of what I have learned about fasting over the past year, written to act as a guide for anyone who may be interested in learning how to fast.
What is Fasting
“The philosophy of fasting calls upon us to know ourselves, to master ourselves, and to discipline ourselves the better to free ourselves. To fast is to identify our dependencies, and free ourselves from them.” ~ Tariq Ramadan
Fasting is voluntary abstinence. You can fast from many things, but we are going to focus on dietary fasting — fasting from food and drink, be it some or all or any combination in between.
Fasting is not starvation, despite popular beliefs. Starvation is when your body suffers damage from lack of energy and nutrients.
When you fast your body burns fat for energy. Fat is stored energy. There is only risk of starvation when you have no fat to burn.
Most fasting experts agree that this risk begins at body fat percentages below 5% (think competitive bodybuilders). For the vast majority of us this isn’t even remotely a concern.
Fasting also refers to the physiological state of being “fasted”, our ultimate objective.
How Long to Fast: The 3 Consecutive Day Rule
Attaining benefits beyond simple weight loss requires you reach and spend time in the fully fasted state. So let’s look at how that happens, then at why we want it to.
The Physiology of Fasting: An Overview
Your body has two basic metabolic states, or processes of producing energy — glycolysis and ketosis.
Your normal state is glycolysis. Here your body gets energy from glucose (sugar) in your blood from the food you eat. Most people never leave this state.
When glucose isn’t available your body has the ability to use fat for energy — this is the metabolic state of ketosis. I know right, fat actually has a purpose! Who knew.
Fasting is the physiological process of transitioning from glycolysis to ketosis. It happens in 4 stages.
- Absorptive State (up to 4 hours into fasting): You eat and your body raises insulin to use the glucose in your blood stream. Extra glucose is stored as glycogen.
- Postabsorptive State (6 to 24 hours into fasting): Glucose in your bloodstream is low so your body begins to break down stored glycogen for energy.
- Gluconeogenesis (24 hours to 2 days into fasting): Glycogen stores have been depleted so your liver begins producing new glucose using amino acids and glycerol to stabilize your blood sugar.
- Ketosis (2 to 3 days into fasting): Your body begins breaking down fat to produce a type of energy known as ketone bodies to fuel your brain.
You need about 3 days to get into full fasting ketosis, then you want to spend a little time there — ala the 3 consecutive day rule.
Now on to why.
Why Achieving Fasting Ketosis Matters
Our objective for fasting, in the most general sense, is to heal. More specifically to permanently heal. True healing results from the interplay of multiple very-complicated physiological processes. I’m only going to discuss two.
One, fasting stimulates a the process known as autophagy. Think of autophagy as your body’s recycling program. It gets rid of old, worn out, malfunctioning parts (cells). Autophagy is good.
Two, fasting stimulates growth hormone production, which signals your body to make new healthy parts to replace the old ones that were thrown out.
Autophagy and growth hormone are stimulated in the presence of glucagon. Glucagon appears when insulin is low. Insulin drops after it has cleared all the glucose (sugar) from your bloodstream. To give insulin time to do this you must stop eating, also known as fasting.
These two processes essential to true healing are at their strongest in the fully fasted state, fasting ketosis.
[Note: If you are interested in reading more about these topics, I have included a list of my favorite resources at the bottom of this article.]
Why Fast: Understand the Benefits & Get Motivated
Fasting is the single most beneficial thing you can do for your health. But knowing that fasting is good for you is one thing, putting it into practice is another entirely.
Before you fast, take a moment to consider why you are fasting — figuring out your why will give you the motivation to drive you towards your goals.
To Improve Your Health — That’s such a boring way to say that, anyway it’s important. We talked about Autophagy and growth hormones. Fasting increases these beneficial processes more than anything else. Consequently, you will have:
- More energy
- Healthier, clearer skin
- Healthier teeth and gums
- Better quality sleep
- A clean and healthy cardiovascular system (lower risk of cardiovascular disease)
- A decrease in anxiety and tension
- Dramatic reduction or complete elimination of aches and pains in muscles and joints
- Decrease or elimination of headaches
- Improve memory and problem solving
- Stabilization of blood pressure
- Stronger and more efficient digestion
- Stabilization of bowel movements
- Elimination of stored toxins
- Improvement with a wide variety of chronic degenerative health conditions, including autoimmune disorders
- Prevent disease and cancer
- Reduce side effects of radiation and chemotherapy treatments
- Increase longevity
To Lose Weight — There are many people who will tell you not to fast for weight loss. I’m sure they have their reasons, but I recommend you ignore them all.
Fasting is the most effective and lasting method for weight loss. You will lose weight, keep it off, and reap a plethora of other health benefits on the side. Unlike dieting, which has essentially no lasting health benefits, but I won’t go there today.
If you don’t want to take my word for it, one well respected proponent of fasting for weight loss is fasting expert Dr. Jason Fung, he writes extensively about it on his blog (one of my favorites). This is his post about fasting for weight loss.
For Fun — For fun? Sure! Fasting is a challenge, and many people see challenging themselves as fun. I do.
Fasting is also an excellent way to alleviate stress, to enlighten your spirit, to meditate, to strengthen your willpower, and to exercise discipline, to learn about yourself, to break addictions. All things that could be described as fun.
We have a philosophy here at LifeBox: Do hard things to do hard things. You will leave better and stronger for it. There is great joy in self improvement.
For Mindfulness — Fasting is a sharp contrast to normality, your regular life patterns. It also presents you with seemingly endless amounts of time. Two qualities that provide an opportunity to turn your attention to other things.
I become increasingly aware of myself when I fast; I feel more open and in tune with the world around me, yet less affected by my environment.
I feel separated, but not isolated, giving me a greater sense of calm and a confidence in my own ability to control myself and how I allow outside influences to affect me.
I find great pleasure in increasing my control over life. I think you will too.
Improve your health, break addiction, challenge yourself for fun, find a sense of calm, grow your inner strength. Once you have your reason you have your motivation. Now here’s what you do with it.
How to Fast
You know how fasting works. Any fear should be gone because you now know how beneficial fasting is for you. And you have latched on to your motivation.
All that’s left is learning how to actually fast.
Never Fasted Before? Have No Fear
Mention of the word fasting sends fear and apprehension through many people, but it shouldn’t. The difficulty is blown way out of proportion.
Fasting is not uniquely difficult. It’s just like anything else you do for the first time, it’s hard because you have never done it before. It gets easier over time.
We already covered the 3 consecutive day rule, which is where we ultimately want to be. This is how you can get there.
My first recommendation is just dive in! After you make it through the first two days your body adjusts and will provide you with energy. Many people even report being overcome with a feeling of euphoria.
If stringing 3 or 4 fasting days together sounds daunting to you, then there are a few methods you can begin implementing to help you adjust to the fasted state and build up towards longer fasts.
Steps for Building Up to an Extended Fast
Step 1: Intermittent Fasting (IF)
The idea is to eat within a specified time window. You already do this every day.
For example: let’s say you sleep from 10:00p to 6:00a, that’s 8 hours. Let’s also assume that you eat your first meal right when you wake up and you last meal right before you go to bed. So your IF schedule would be annotated as 8:16–8 hours fasting, 16 hours feasting.
Work towards transitioning more of your time into the fasted state.
Make a rule that you won’t eat after 8:00p; you are now at 10:14 IF. Then try pushing breakfast back until 8:00a, so no you are only eating from 8:00a until 8:00p making your IF Schedule 12:12.
Next try skipping breakfast! Make lunch at 12:00 your first meal of the day, an IF Schedule of 16:8. It may take a week to adjust, but before long your body won’t even be hungry until lunch time and you will feel great in the mornings!
[I’ve been doing IF for 6 months. My schedule is 18:6, so I only eat from 2:00p to 8:00p every day. I feel great and am never hungry in the mornings. I even work out fasted every day at 12:00, right before I eat. I love it.]
Step Two: Single Day Fast
Next try a single day fast, which won’t be any big deal now that you are already skipping breakfast every day.
Aim for a 24 Hour fast you first time. For example: You finish dinner on Monday at 7:00p, skip breakfast and lunch on Tuesday, then eat dinner Tuesday night at 7:00p. You just fasted for 24 hours! Doesn’t sound so bad when you realize that it just means skipping two meals.
Next try a 36 hour fast, a true one day fast. Example: You finish dinner on Monday at 7:00p, skip breakfast and lunch AND dinner on Tuesday, then eat breakfast Wednesday morning at 7:00a. Boom, you just did a full day fast. You’ll be surprised how easy it is, I promise.
Eat breakfast on Wednesday?? But I’ve been intermittent fasting and never eat breakfast. Well I’m glad you brought it up, just push your “break fast” meal back to your normal lunch time and you have a 42 hour fast!
Now that you are comfortable with the idea and practice of fasting, you are ready to begin your first full 3 day fast (84 hours). Here’s how to get ready.
Preparing for Your First Extended Fast
Types of Fasting that Fit Our Criteria
There are all sorts of variations of fasting, and with that comes a lot of questions. Should you drink juice? Can you eat some food, and if so what should it be?
In order to receive the full spectrum of health benefits, it’s important that your body has enough time and nutrient deprivation to go into ketosis — to do so your fast should meet the following criteria:
- Should last a minimum of 3 full days (84 hours)
- Consume no more than 725 calories per day
- Important for anyone who is juice fasting, or fasting mimicking
Purists would disagree with this criteria, but consuming up to 725 calories has been scientifically proven to deliver the same benefits as pure fasting and it is much easier to fit into your normal schedule — it’s called fasting mimicking and it is what I do each month, with the occasional exception.
That being said, the longer and purer (closer to water fasting) you go, the more effective your fast will be.
Regardless of the type of fast you will be doing, here’s how to get prepared.
The Days Leading Up
Get Your Mind Right — We spoke about understanding the benefits and defining your own objectives. Make it personal and get motivated!
Adjust Your Expectations — Fasting is a powerful practice, but it’s not a quick fix. This is about progress, it’s not a panacea. Be proud of yourself for the steps and improvement you are making!
Prepare Your Body — We’ve already talked about building up to longer fasts. Additionally, I recommend cleaning up your diet a few days before your fast. Cut out sugar and carbohydrates; this will lower your blood sugar and ease the transition.
I confess that I don’t do this. I’m not sure it makes a huge difference, but mostly because I fasting mimic. When you fasting mimic you get a small amount of calories; it really makes a huge difference during the transition.
Talk to Your Doctor — Your body and medical history are unique, go talk to your doctor just to see if there are any special precautions you should take. It’s always good to consult an expert, especially when it comes to your health.
How to Fast Safely
Barring extreme cases, fasting is not dangerous. But safety is sexy, so here are a few things you can do to be sure you have all your bases covered.
Do Your Research — Like any worthwhile endeavor, you should do some reading and studying before you dive in. Take some time to get familiar with fasting in order to gain a better understanding of what to expect. (I’ve linked some sources at the bottom)
Rest — Many people will tell you to suspend all normal activities. I don’t think that is necessary. Just be sure to get a full night’s sleep and be aware of how you feel. If you get tired, take a nap!
Get Some Sunlight — Sunlight exposure will greatly improve your experience. Sunlight contains essential vitamins and releases hormones in your body that boost your mood. Who doesn’t love getting some fresh air?
Stay Hydrated — To transition from the fed state to the fasted state your body must use up your glycogen stores. Glycogen holds a lot of water, so when it leaves a lot of water weight goes with it, which could cause dehydration. So be sure you drink enough water.
There are many different opinions on how much water is enough, my rule is to drink when you are thirsty. An indicator that you are well hydrated is clear or a very pale yellow urine.
Consider Supplements — Purists may also balk at this, but supplementing could ease the side effects of fasting. Consider taking a multivitamin.
If you are a fitness devotee worried about your muscle mass, don’t be because fasting doesn’t consume muscle. But you can supplement with BCAAs for some extra muscle protection. Just be sure to get ones without calories.
Fasting with Diabetes — There are many cases where fasting has reversed Type II diabetes. It is a powerful practice and one well worth considering for anyone suffering from chronic diseases.
If you are diabetic (Type II), my recommendation is to talk with your doctor. You may want to consider how to adjust your medication while fasting to account for lower glucose levels, among other things.
Tips to Make Fasting More Enjoyable
Don’t Tell People You Are Fasting — Fasting is widely misunderstood. Most people who aren’t familiar or at least curious about alternative health lifestyles and natural healing practices won’t understand what you’re doing. They will most likely react negatively, disapproving and encouraging you to stop. I recommend just saving yourself the trouble and not telling people.
I tell my family or close friends when I am fasting, and encourage you to do the same. Pick someone who will be receptive and supportive. It’s good to have someone checking in on you and encouraging you!
Dealing with Hunger — Before my first fast, I expected to feel like I was starving the whole time. That wasn’t the case. You will feel hungry the first two days while your body is still transitioning, but after that the hunger subsides.
Here’s a few things you can do if you get hungry:
- Drink some water. Drink a big glass first thing in the morning too. Staying hydrated prevents hunger.
- Have a glass of green tea. This will have similar effects as drinking water, plus the added benefits of antioxidants, which may stimulate your metabolism and boost weight loss. Also, green tea is just delicious!
- Eat some chia seeds. Chia seeds are rich in fiber and omega 3 fatty acids. They absorb water, so you can soak them to make a pudding like substance that you can eat to get some weight in your stomach. Just be conscious of the added calories.
Stay Busy — Planning, gathering, and preparing meals consumes a lot of time. Not doing those things leaves you with a lot of extra time on your hands, so find some activities to keep you busy. Get a good book, or go for a walk, or start a new project you have been wanting to do!
Avoid Stress — I’ll admit that for the first two days of a fast I get a bit moody / emotionally sensitive. So I avoid things (and people) that stress me out. If you know something or someone that puts you on edge, avoid it for a few days.
Track Things — Weight loss is an evident benefits of fasting, but most of the real benefits are unseen. I like to track these — it’s fun to know how fasting is affecting your body and adds extra encouragement to see health improvements on paper.
Get a lipid profile taken before you start fasting. You can then get one every few months to track your cholesterol numbers, blood pressure, and other inflammatory markers.
Exercise — There are different opinions about this, but I find exercise to be enjoyable while fasting — some forms more than others. I have experimented with crossfit, weightlifting, running, and yoga while fasting.
When I water fast, I get the best results from steady state activities like running (or biking) and yoga. I found it difficult to recover well after higher intensity stuff like crossfit and weightlifting.
When I fasting mimic, I am able to recover just fine after participating in crossfit and weightlifting. So that’s another advantage of the FMD.
You can read more about how fasting affects your body during exercise here.
What to Do About Constipation — I’ve never experienced this, but it seems to be a common concern so I will quickly address it.
If you aren’t eating, you simply may not have any waste to expel. However, if you feel the urge to go and cannot, consider drinking more water as you may be dehydrated. If the problem persists a small dose of a stool softener will probably do the trick. Just remember to drink more water than you think you need if you take a softener or laxative.
How to End Your Fast
“More caution and perhaps more restraint are necessary in breaking a fast than in keeping it.” ~Mahatma Gandhi
Gandhi had just come off a 40 day fast, so you can see his point. The longer you fast the more precaution you should take. I do believe that the difficulty of ending a fast is overstated in most instances.
The transition back to glycolysis from ketosis could make you sluggish and possibly a little sick. But with a few tips these are easily avoidable.
When You Fasting Mimic
When I Fasting Mimic (5 days at 725 calories) I have absolutely no problems or discomfort when breaking my fast. Not having an extended transitional refeeding period is a huge benefit of fasting mimicking, especially for athletes looking to get back to training regimens.
It’s become a habit now to break my fast with a Chik-fil-a breakfast on Friday morning. I get a spicy chicken biscuit combo with extra Chik-fil-a sauce — it’s magical.
I have noticed that how sluggish I feel after “break fast” is directly associated with the meal size and the amount carbohydrates and sugar it includes. So the fresher your breakfast, the better you will feel and the easier you will transition back to glycolysis.
Everyone is going to be different, so eat something small and clean the first time and see how it goes. Then you can experiment from there.
When You Water Fast
Breaking a water fast is a different story. Your stomach is going to be much more sensitive.
After reading the ample cautionary tales scattered across the internet about breaking a water fast, I decided to ignore them all and just feast. Partly because I wanted to see how it would compare to breaking a fast after FMD, and partly because I tend to think our bodies aren’t as fragile as most people think.
So I ended my 5 day water fast by consuming homemade peanut butter cups, key lime cheesecake bites, bacon, and eggs. About 5 minutes later I was in the bathroom with stool of questionable consistency. It quickly passed and never returned, thank goodness. I ate a dinner, albeit small, of chicken pot pie about 3 hours later and was back to normal.
All that to say I recommend easing into your first meal with something small and light, then after that you should be fine. Longer fasts require greater precautions when refeeding. Here are a few principles to safely break an extended water fast.
- Eat fresh whole foods — fruits, vegetables, and greens. It is important to eat them whole to get the fiber so as not to spike your blood sugar too high.
- Eat a small amount, which you will do naturally because your stomach will have shrunk significantly, then waiting a few hours afterward to see how you feel.
- Continue eating whole foods and begin adding protein and dairy, again giving your body time to respond after each meal before you continue eating.
- Listen to your body. If it doesn’t like something then stop eating it!
- Fasting is the act of abstaining from food for mentally and physically beneficial purposes.
- Extended fasting is defined as any fast of 3 days or longer, and is necessary to receive permanent health benefits.
- Find your motivation for fasting whether for weight loss, health improvement, fun, or mindfulness.
- If you are new to fasting, consider working up to an extended fast by first intermittent fasting then by completing shorter single day fasts.
- To safely fast always do your research, get plenty of rest, avoid stressful situations, get some sunlight, and discuss any additional precautions with your doctor.
- While you are fasting, stay busy and don’t be afraid to exercise!
- End your fast by eating small amounts of fresh whole foods and giving your body time to respond. Once you are sure that your stomach is good, proceed with joy.
- Lastly, don’t be afraid of fasting. It’s doable for anyone and gets easier the more you do it.
You probably have a burning question, ask me in the comments!
Don’t forget to click that little heart (💚) over there so other people can start fasting.
- Fasting — Intensive Dietary Management by Jason Fung
- The Fasting Series by Celestine Chua
- Fasting Wikipedia
- Fasting Can Save Your Life (A book, by Herbert M. Shelton)
- Fasting and Eating for Health: A Medical Doctor’s Program for Conquering Disease (A book, by Joel Fuhrman)
- Fasting Experience Reviews worth a read
- Nat Eliason
- Ben Marcus
- More About Autophagy
- Fasting and Autophagy by Jason Fung
- Ways to Stimulate Autophagy by Greatist
- The Science of Ketosis: The Eating Academy by Dr. Peter Attia