Intermittent Fasting: Frequently Asked Questions

(DISCLAIMER: This is an older article in need of some minor editing.  I've left it up on the site because it contains valuable insights and answers many important questions.  While I still recommend reading it, this piece isn't representative of the refined quality of other posts)

What is Intermittent Fasting?

Intermittent Fasting is simply a different way to eat.  It’s a lifestyle that runs counter to the conventional “three meals a day" approach.  There are plenty of complicated protocols out there but the principle is always the same: Extend the amount of time you spend in a fasted state every day.  Technically speaking, everyone fasts for an extended period of time while they’re sleeping.  But with Intermittent Fasting, the goal is to extend that period of fasting.  The most common way to accomplish this is by setting a four to ten hour “eating window” for yourself during the day.   I typically use a six hour eating window (between 4pm and 10pm) which leaves me fasting for the remaining 18 hours of the day. 

Why Do You Put Yourself Through This? 

The main reason I do Intermittent Fasting is to make my lifestyle more enjoyable.  As a trainer and fitness coach, I like to keep my body lean and muscular.  Most people think that it must be easier for me to maintain a low body fat percentage all year round, but it’s actually not.  I’m very prone to overeating and gaining weight.  The difference is that I’ve figured out how to make eating the right amount food satisfying and enjoyable every single day.  The way I do that is with Intermittent Fasting.  By saving a majority of my calories for later in the day, I’m able to eat my favorite foods, and a lot of them, every day.  The approach I’ve crafted for myself isn’t exactly “The Warrior Diet” or “The Eating Window”, but it’s a combination that’s right for me.  Simply put, I do Intermittent Fasting because it allows me to enjoy the process of achieving my fitness goals. 

I encourage everyone to question the conventional ways of doing things, especially eating.  Just look around, two thirds the people in our country, young and old, are overweight or obese.  A majority of these people eat 3 square meals a day and some snacks in between.   Surely you've heard the phrase, “If it’s not broken, don’t fix it”.  Well something's broken with the way we eat and we need to fix it!  

Ultimately, it’s up to you to fix it by finding the most enjoyable way to eat the proper amount food.  That might be three square meals, it might be fasting, and it might be eating six smaller meals.  The possibilities are truly endless but it’s your job to find the way that lets you enjoy leading a healthy lifestyle.  For me, that’s intermittent fasting.  

Why Intermittent Fasting? (The Psychology)

Most people who do Intermittent Fasting do it because they find that following a fasting protocol makes losing weight or maintaining a low body fat percentage easier and more enjoyable than it is when eating in a more conventional way.  There are also a myriad of health benefits that come with extended periods of fasting, but first, I want to emphasize the psychological component that makes fasting a satisfying way to live.  Intermittent Fasting lets you eat big, satisfying meals even while maintaining a calorie deficit.  If you’re only eating for 4-8 hours of the day, you get to eat your entire day’s allotment of calories in that small window of time.  That means big meals, delicious foods, and keeping your favorites in the dietary line up. 


Why Intermittent Fasting? (The Biology)

There are a number of health benefits that come with Intermittent Fasting as well.  The most significant of which have been validated by scientific studies and have the benefit of making fasting (the not eating part) easier than most people think it is. 

For most people, when they hear that Intermittent Fasting consists of not eating for up to 20 hours of the day, they have a single, major concern.  The concern is that people who fast must be hungry and miserable all the time.  This is a perfectly reasonable assumption, but you can actually train your body to adapt to an Intermittent Fasting eating schedule.  There's a brief adaptation period that occurs while your hormones gradually set a new cycle for themselves, but after that, it's really not that bad.   Don’t get me wrong, the first days of fasting are pretty tough, and even the first weeks can be a bit of a challenge, but after that it’s smooth sailing.  

Won't I just be hungry all the time? 

 You may have heard of circadian rhythms before, but I bet you didn’t know that they affect when you get hungry.  The bottom line is that all of your hormones and neurotransmitters are released according to a cyclical schedule throughout the day.  Your circadian rhythms set these cycles and if you’ve ever had jet lag, you know how crippling it can be to have your circadian cycles out of whack.  Well, your circadian clock is primarily set by three things; light exposure, food intake, and exercise.  Specifically, it’s the time you’re exposed to light, the time you eat and the time you exercise that set your rhythms.  So, if you train your body to eat during a specific time of the day, it will adjust by resetting its hormone release patterns so that the “hungry and tired” hormones aren’t released until close to your eating window. 

Fasting actually promotes alertness and energy.  By increasing circulating levels of Nor-epinephrine in the brain and the body, Nor-epinephrine stimulates lipolysis (fat burning), alertness, and energy.  In fact, prescription drugs for attention deficit disorders, like Adderall, boost levels of Nor-epinephrine and another neurotransmitter, Dopamine, in the brain.  That's not to say that fasting is the equivalent of taking an ADHD medication.  However, you'd be surprised by how energetic you can be even after going twenty hours without eating.    


Won't I lose Muscle While Fasting? 

The second concern most people have, specifically exercisers, is that they’ll lose muscle mass while they fast.  However, fasting has actually been shown to boost growth hormone levels, which acts to preserve muscle tissue at the expense of fat.  The reason for this is that, for the sake of simplicity, insulin and growth hormone basically counteract each other.  Insulin, which is released in response to calories from food entering the blood stream, is the universal “storage hormone”.  It makes your muscle and fat cells take up the calories from your blood and therefore enable you to use the energy that food provides.  In times of fasting, growth hormone has the opposite effect.   It triggers your fat tissue to release its caloric contents back into the blood for use by your muscle and other tissues when there isn’t any from food.  This relationship is well established scientifically.  In fact, in a 1988 study published in the Journal of Clinical Investigation (Ho et. al 1988) demonstrated the biological mechanism for this phenomenon by showing a four-fold increase in growth hormone release on a 24 hour fast and a ten-fold increase by day four.

This is a beautifully logical and life preserving evolutionary adaptation.  To demonstrate this, imagine you’re a Mongolian tribesperson living in the 1100s.  Since evolutionary changes to human biology occur on the timescale of tens of thousands of years, your hypothetical biology in this imaginary situation is virtually identical to your current biology.  You’ve been out on a hunt with members of your tribe for the past 3 days.  You haven’t eaten since you left camp but you still need the physical power and mental alertness to hunt down and kill your next meal.  Your insulin levels are at their minimum, your growth hormone is spiked to maintain your muscle's ability to function and you have lots of Nor-epinephrine flowing through your blood to keep you alert and energetic.  None of us would be here today if our ancestors’ bodies hadn’t evolved to handle the stress of prolonged fasting. 


Can I Exercise Fasted? 

Intermittent Fasting isn’t specifically for athletes or hardcore exercisers, but it is an effective way for them to eat.  Professional athletes, celebrities, and even endurance competitors swear by intermittent fasting.  The wake promoting and body composition benefits can be obtained by anyone though.  The one major exception is for people who exercise first thing in the morning.  Early morning training sparks up a pretty big appetite and the last thing you’ll want to do after an intense workout is wait six hours before you eat anything.  That being said, it’s perfectly safe to exercise fasted and some people (like me) actually prefer to exercise fasted.  There’s even evidence to suggest that cardiovascular exercise while fasted may promote fat loss beyond what is possible with food in the system.


So how do I get started? 

I want to emphasize how important the adjustment period is.  In order to make the biological adjustment possible and tolerable, you have to ease into it.  I recommend starting by skipping breakfast and pushing your first meal back further into the day.  Likewise, gradually reduce the size of your meals earlier in the day until it feels like you don’t need them.  Both of these tactics will help you save your day’s allotment of calories for a condensed amount of time later in the day. 

Are there any tricks to make it easier? 

 Fasting can be hard at first and it won’t stop being difficult immediately.  Thankfully though, there are plenty of little tricks that can help make fasting easier.  Here are the tricks:

·      Use Coffee/Caffeine Strategically:  Caffeine is well known for it’s appetite suppressing and stimulant qualities.  Drinking caffeine during your fast will blunt your hunger, give you an energy boost and mimic the comforting routine of having breakfast.  I find that I look forward to my first cup of coffee in a very similar to how I used to look forward to breakfast when I’d have breakfast every morning.  Just remember, the whole point of fasting is to delay your calorie intake for later in the day so you shouldn’t be adding anything caloric to your coffee.  Zero calorie sweeteners are fine, but no sugar or whiteners.  If you’re not a coffee person, other sources of caffeine are perfectly acceptable as long as they don’t contain calories.

·      Drink Sparkling Water: The carbonation of the sparkling water will soothe the stomach grumbles that can accompany the fasted state.  Likewise, the fizziness will activate some of those stretch receptors on your stomach to send a signal to your brain that you’re full.  Just like the coffee, zero calories is the goal here.  I like to drink flavored seltzer, but there are plenty of other great options.

·      Chew Gum: The simple act of chewing actually stimulates the secretion of stomach soothing fluids.  By chewing gum, you temporarily trick your body into thinking that you’re eating so it preps the stomach for the food it thinks you’re about to swallow.  Chewing gum is another way to sooth the stomach grumbles and to keep food cravings at bay. 

·      Use Fruit to Refill Liver Glycogen:  Our bodies have two primary ways to store and use energy.  The preferred method is converting glucose into a glycogen, a starchy, storage form of carbohydrates that can be found in your liver and muscle tissue. Your muscles convert these glycogen stores back into glucose so they can produce the energy necessary to contract.  So if you do 4 sets of biceps curls, you’ll be using up a portion of the glycogen stored within the biceps muscle tissue.   Your liver glycogen on the other hand, is converted back to glucose in the same way, but this glucose is used to fuel more general, widespread energetic processes like breathing, walking, thinking, etc.  Your liver glycogen stores start running low about four to six hours into wakeful fasting.  This triggers an intense and genuine hunger signal because your body desperately wants more glucose to use as fuel.  You can tame that hunger by eating a piece of fruit.  Fruits are rich in simple sugars that your body will immediately use to refill its liver glycogen stores.  The result is another couple hours of comfortable fasting without the return of intense hunger. 


I've heard of different ways to do IF, what are some of the most popular approaches? 

The most common way to do intermittent fasting is the “Eating window” approach.  This method consists of choosing a 4 to 10 hour window during the day as your only time to eat and for the remaining 14 to 20 hours you’re fasting.  This method, while simple, can be hard to follow, especially at first.  While sticking to a designated eating window will insure the purity of your fast, the strictness of it can make it hard to stick to.  However, some people swear by this method and once your body is adjusted, the eating window isn’t hard to stick to. 

The other common way to do intermittent fasting is to follow the principles of “The Warrior Diet”.  Made famous by Ori Hofmekler, The Warrior Diet consists of eating only small snacks of mostly fruits, vegetables, and nuts during the day and then consuming the rest of the day’s calories in one large meal at the end of the day.  While not strictly considered “fasting”, this protocol does preserve the psychological benefit of being able to eat big, satisfying meals even at a calorie deficit.  For more information on The Warrior Diet, simply Google it and look through Hofmekler’s site.

Precautions and Who Shouldn’t do Intermittent Fasting

While Intermittent Fasting is perfectly safe for most people, there are few special populations who should think twice about it.  Those populations include:

·      Children

·      Those with Diabetes or prone to hypoglycemia

·      Females with low body fat percentages who are prone to irregularity of their period.

·      Those with eating disorders, especially Binge Eating Disorder and Bulimia

The biggest safety risk with intermittent fasting is not eating enough calories to support health.  That may sound crazy, but if you consistently go dangerously low on your daily calories, all sorts of health problems are coming your way.



What does a day of Intermittent Fasting Look like? 

How I do Intermittent Fasting: Ditching the Dogma

I’ve tried just about every fasting protocol there is and found that following a strict “eating window” or meal schedule can be very overwhelming and restrictive.  The whole point of this is to make maintaining an appropriate calorie intake enjoyable, so lets ditch the dogma.  All you have to do is delay that first meal as long as you can into the day, then hit your calorie target in as satisfying a way as you can.  Finding the most enjoyable way to do this becomes something of an art form, and once you’ve found your rhythm, every day becomes incredibly satisfying.  Here’s what a typical day of intermittent fasting looks like for me:

I wake up around 8:00am; I wash my face, brush my teeth, and get my backpack ready to go to the library, class or work.  I drink at least 16oz of water right when I wake just to put something in my stomach and stay hydrated.  About an hour after I wake up, I’ll have a cup of black coffee.  No sugar, no cream, no milk, nothing, just black coffee.  The coffee does two things.  First, it blunts my hunger and gets me going with my day without thinking about eating, and second, the stimulant effect compliments the fasted state of mental clarity so I can be extremely productive in the morning.  After a couple hours of getting work done, I implement trick number two for blunting hunger; I drink sparkling water.  Again, zero calories, just sparkling water.  The carbonation helps sooth my stomach and keeps being in the fasted state very pleasant as the afternoon hours approach.

            In the afternoon I start feeling genuinely hungry.  It takes some getting used to, but once you’ve adjusted to intermittent fasting, it’ll be easy to discern the feeling of genuine hunger from the benign, morning stomach grumbles.  Usually around 2 or 3 o’clock in the afternoon, I’ll break my fast with a piece of fruit.  This is another trick to prolong the fasting period.  The genuine feeling of hunger you’ll experience about four or five hours into fasting is the result of your liver’s glycogen stores being depleted.  I’ll go into more detail in a minute, but the piece of fruit allows for a quick refill of that liver glycogen that’ll give you a few more hours of comfort before your first real meal. 

            After my piece of fruit, I usually go work out.  Whether it’s a lifting day, a cardio day, or just a recovery/mobility day, I’ll spend somewhere between one and two hours at the gym.  Yes, I workout fasted.  After my workout is when the fun starts.  Around 5 or 6pm I’ll have my first real meal.  I like to start with a big salad with some type of meat on it.   By the time I finish that meal, I’m at around 700 calories of total intake and it’s already almost 7pm.  While that meal is being digested, I feel my parasympathetic nervous system kicking in as I’m put into a more relaxed, and happy mental state.  After a couple more hours, usually around 9pm, I’ll go out to eat with some friends.  I’ll eat a huge meal of anywhere between 1000 and 1500 calories.  I make sure that this meal is satisfying on multiple levels.  I always get a portion of starchy carbohydrates like potatoes, sweet potatoes, rice, or even French fries with a decent serving of protein (usually meat) and a moderate amount of fat to create the perfect taste experience. 

            After this relaxing meal with my friends, we’ll either hang out for a little while or I’ll go back to my place to get ready for the next day.  Once I have everything squared away and I’m ready to go to bed, I’ll have my last meal of the day.  I love chocolate and ice cream, so I’ll have some yogurt or a protein bar and then a chocolate bar, some ice cream, or even both.  That leaves me feeling full, relaxed, happy, and most importantly, completely satisfied after eating less than 2500 calories. 

            This is just an example of a typical day in my life with intermittent fasting.  You can obviously tailor your food choices and meal timing to fit your life and schedule.  The key thing to remember is that you’re trying to find the most enjoyable way to maintain an appropriate calorie intake so you can reach your fitness goals.  Dieting doesn’t have to be miserable.  If you genuinely enjoy the process, your goals are as good as conquered. 


Wait, won't people think I'm crazy? 

A very under looked consequence of deciding to start intermittent fasting is that people are going to think you’re crazy for eating like you do.  The best way to avoid the people in your life constantly confronting you about your eating habits is to keep them very low key.  Take a page from the movie Fight Club’s book and treat it like “The first rule of fasting is: you don’t talk about fasting.”  Simply go about your day and don’t make a big deal about.  Reading this article has inevitably prepared you for the confrontations you’ll have with your friends and family.  But if you want to share your new approach with the people in your life, here’s a simple explanation for why the notion of needing to eat breakfast is so prevalent and why it’s not true:

If we look back through human history, it’s abundantly clear that the whole idea of starting the day with a meal can only be the product of cultural constriction in a society with an abundant food supply and the technology to keep that food fresh for extended periods of time.  However, an overwhelming majority of human history played out in an environments where this was not the case.  Even your ancestors who lived in the 1700s probably didn’t live in a society where an abundant and well-preserved food supply allowed them to eat breakfast everyday.  Keep in mind that evolutionary changes to our biology happen on the time scale of tens of thousands of years, not hundreds.  As a result, your biology is virtually identical to that of your ancestors who lived in the 1700s and even to that of your ancestors who lived in the time of ancient civilizations.  This means that your body is hardwired to handle prolonged periods without food.  In fact, we’re designed to operate optimally and efficiently in the fasted state because that’s the state our ancestors (and our imaginary Mongolian tribesperson) were in when they were hunting and gathering their food. 

However, if you’re reading this, you and everyone you know, probably live in a society with abundant access to a well-preserved food supply. Odds are your parents live in such a society, and odds are their parents did too.  So your parents, your parent’s parents, your friends, your friends’ parents, and even your friends’ parents’ parents, were all raised to think that eating breakfast is simply what you do.  But, remember how relatively recent the development of the ability to always eat breakfast was.  Remember that you’re biologically identical to the Mongolian tribesperson in our example.  And most importantly, remember this: The food environment in which humans evolved created the necessity to be mentally sharp, physically energetic, and metabolically efficient for prolonged periods of fasting.  If our biologically identical ancestors could fast for three, four, even ten days at a time, we can all certainly handle it for four to six hours after we wake up



Intermittent fasting is an amazingly powerful way to get lean and stay lean for two complimentary reasons.  The first is that the fasted state accelerates fat loss.  The second, and more important reason is that the intermittent fasting lifestyle lets you truly enjoy the process of losing weight.  The enjoyment and satisfaction that comes with intermittent fasting is what sets it apart from traditional dieting. 


Want More Info?  

Check out my Comprehensive Guide to Intermittent Fasting!  This 12 page article tells you everything you need to know to get started with Intermittent Fasting. 


Evan ShaulsonComment