Beginner's Guide to Intermittent Fasting

You're here because you want to learn how to intermittent fast, and you want to learn how to do it without feeling frustrated and half-starved. You've come to the right place!

We have, quite literally, written the book on intermittent fasting, helping thousands of our BodyRock #FitFam see the benefits of fasting first hand and in the flesh. Keep reading: we're going to help you learn how to intermittent fast too.

What is Intermittent Fasting?
Why Intermittent Fast?
Intermittent Fasting and Cellular Health
Intermittent Fasting and Insulin
Intermittent Fasting and Muscle 
Intermittent Fasting and Hormones
Female Hormones and IF
Male Hormones and IF
Your Brain on Intermittent Fasting
Your Emotions on Intermittent Fasting
Intermittent Fasting Nutrition Basics
Getting Started: How to Begin Intermittent Fasting
Intermittent Fasting Workout


What is Intermittent Fasting?

Before you learn how to intermittent fast, get a handle on what it is, exactly.

Intermittent fasting involves using short, sustainable periods of fasting combined with shorter periods of eating to lose fat, gain muscle, balance hormones, increase productivity and basically live a longer, happier life. During these periods of fasting, you can drink water, black coffee or tea, but you cannot eat or drink anything with caloric value or anything that can affect your blood sugar levels.

While some types of intermittent fasting involve not eating for 24 hours, the type of intermittent fasting most commonly used is the 16:8 method, meaning fasting periods are around 16 hours long and eating windows are within a spread of 8 hours. Which exact hours you choose to fast and eat will depend on your lifestyle and personal preferences, but the majority of fasting is done while you are asleep. 

For example, if you are a night owl and rarely go to sleep before midnight (or later), your fast could start around 10pm and go until 2pm the next day. If you are getting a decent sleep, this only gives you approximately 6 hours when you’re awake the next day and not eating. That’s it. 

Another example: you go to bed each night around 9pm. In this case, you could stop eating at 6pm and eat the next day at 10am. Again, you get to pick your fasting and eating slots to suit your life. 

Why Intermittent Fast?

Intermittently fasting is nothing new, but  — especially in recent years — it’s been viewed with almost equal measure of confusion, misunderstanding and skepticism. This is understandable. Fasting seems to go against so much of what we’ve been taught about eating. Aren't we supposed to eat within an hour of waking? Aren't we supposed to eat many smaller meals a day? Aren't we supposed to refrain from eating carbs before bed? Shouldn’t we eat an hour before exercising? And no more than an hour after? 

By all accounts, intermittent fasting turns every single one of these much-touted dietary commandments on their heads. It turns them on their heads, and it still gets results. Not slow, plodding, hard-won results, either. People who have had no luck with traditional lifestyle overhauls have incredibly easy and fast results with intermittent fasting. 

The reason it works is threefold, and all three folds are connected: Intermittent fasting works on a physical level, a psychological level and an emotional level. It’s an invariably powerful trifecta.

Intermittent Fasting and Cellular Health

Intermittent fasting has been shown to reduce inflammation as well as oxidative stress, which in turn bolsters the quantity and quality of cellular mitochondria (the parts of cells that convert fats, proteins and sugars into the chemical energy the body uses to live) while simultaneously stimulating autography (the process of cellular self-cleansing and apoptosis or ‘cell death’). This is good because when a cell doesn't die when it’s supposed to, it can begin to grow at an uncontrolled rate, developing into potentially cancerous tumours. Translation: intermittent fasting helps your cells look and feel healthier and younger and run more effectively and, therefore, you look and feel healthier and younger. 

What’s more, by positively influencing the cellular and metabolic systems, intermittent fasting strengthens the whole body, protecting it against disease as well as bolstering the neuron responses that usually lag with aging. As a result, Intermittent fasting is also credited with improving brain health and protecting against degenerative brain diseases.

Intermittent Fasting and Insulin

Intermittent fasting can also help regulate insulin response. Insulin's function is to encourage the storage of energy. When we eat, our insulin levels increase and fat is held, untouched, in our fat cells as our body uses the glucose in the bloodstream. During this stage of insulin influx, the fats cannot leave the fat cells. However, when you fast, you lower insulin, thereby increasing lipolysis  — the rate of fat breakdown. And since your cells are healthier, this can and will happen more effectively and efficiently.

Intermittent Fasting and Muscle 

While intermittent fasting helps you lose fat, it has been shown to also help you build muscle. This is in large part due to the fact that intermittent fasting can increase human growth hormone by up to five times. In addition to further fueling the fat burning process, a higher level of human growth hormone will also support major muscle gains. 

Intermittent Fasting and Hormones

The rebalancing of hormones is one of the main reasons intermittent fasting works for so many people who have been failed by conventional healthy eating advice. It’s not that these traditional methods are wrong, but that hormonal changes within your body have rendered them useless for you. 

Just like one pair of shoes won't fit you from childhood to adulthood, neither will one diet. You change. 

Because intermittent fasting can help you reset and balance your hormones, it is arguably the most effective and easy lifestyle change you can make to keep your body and mind healthfully running at prime. 

Ultimately, learning how to intermittent fast can help balance hormonal disruptions and a healthy hormone balance has been shown to improve quality of sleep, bolster mood, and even enhance sex drive and sexual pleasure.

So, let’s recap. Intermittent fasting can help your body by:

Improving cellular health and thereby warding off heart disease, cancer, diabetes and degenerative brain diseases, like Alzheimer's. 

  • Helping you lose fat
  • Helping you build muscle
  • Increasing longevity
  • Improving mood
  • Improving sleep
  • Helping you adapt to hormonal changes that negatively impact health

Your Brain on Intermittent Fasting

We’ve already touched on how intermittent fasting can impact the health of your brain by improving neuron response and increasing cellular health. Another way in which learning how to intermittent fast can help make your brain healthier is through its effects on cognitive function. By easing your mind’s physiological focus on activities having to do with eating, digestion, energy allocation and storage and hormone control, your brain can function more clearly and more effectively. This will usually start to happen 4-5 hours after eating, since this is typically how long it takes to digest a meal. Of course, you will likely be asleep during this time, but the benefits will extend to your waking hours.

With more optimally balanced hormones, cortisol (stress) levels drop into a healthier range, improving memory, concentration and focus. It is in this state that we are better able to make the distinction between real hunger and psychological hunger, and understanding the difference between the two is crucial.

What is psychological hunger?

Psychological hunger is a conditioned or external response rather than a real, physiological need. You want to eat because you've been conditioned to eat at a certain time or because you're sad or tired or angry or happy or just because there's delicious food in front of you. But what you are not is truly hungry. 

So I won’t feel hungry?

We’re not going to join the ranks of countless other programs that claim that if you do their program, their way, you will never feel a single hunger pang. So the answer is yes, you may feel hungry  — especially during the first few days while your body adjusts. But it will adjust.

Thanks to increased willpower due to clearer cognitive function and a change in your body’s secretion of ghrelin, the hunger hormone, which Intermittent Fasting can help you control. 

The more you can avoid answering the urge to eat, the more your ghrelin timing and production will adjust. As a result, you’ll condition your body and brain to embrace the new fasting schedule. 

Most people who intermittent fast find their ability to control their appetite better than ever before. 

Yes, at first you may feel hungry, but no, you will never truly be hungry. The majority of us are lucky enough that we never have (and never will) experience the real depths of hunger: the sort that causes fear and panic and desperation. You will not be starved or even deprived, because you will be hitting your macros every single day and even indulging in eating the foods you love.

Intermittent fasting is designed to keep your hormones optimally balanced and your body optimally fed so that you don’t actually experience devastating and deterring deprivation. Ever. Not for one minute. In fact, once people learn how to intermittent fast, they often have trouble eating as much as they have to each day during their eating window.

The hunger you may feel in the beginning — and the hunger many of us feel when we feel peckish — is simply a combination of our conditioned ghrelin production and that psychological hunger. Sip on a herbal tea. Have a cup of black coffee or glass of water. Take a moment to remember: psychological hunger may be uncomfortable at first, but it is not real hunger, and once you learn to make the distinction between that and real hunger, it will actually go away.

Your Emotions on Intermittent Fasting

Intermittent fasting allows you to liberate yourself from an arduous emotional relationship with food. One of the main ways it does this is by limiting the time you have to spend thinking about eating. There are only 8 hours during the day when eating is even an option. The rest of the time, it is literally and figuratively off the table. 

During your fasting periods, you can free your mental space up for other things: work, family, personal projects. You’ll adjust to this new eating schedule and learn you can make changes that you never thought possible, more easily than you would have believed. You will see how much time you wasted being a slave to an arbitrary (and even dangerous) eating schedule. 

For many of us who have spent years (if not a lifetime) obsessing about food, the freedom afforded by intermittent fasting can be absolutely life changing. Food becomes something that can delight us, sure, but never control us. 

It’s about balance, remember, and intermittent fasting balances your mind, body and spirit. You’ll look great, feel incredible, and be inspired. 

Who Shouldn't Intermittent Fast

Despite all the incredible benefits brought on by intermittent fasting, there are some people who should abstain from the practice as a lifestyle choice due to their more complex energy requirements. These people include:

  • Children
  • Pregnant women
  • Nursing women
  • Women in early postpartum

While everyone should consult with their healthcare provider before beginning intermittent fasting (or any change to diet or exercise), there are some people who absolutely need to be cleared. These people include:

  • Athletes
  • Diabetics
  • Those with gout
  • Those taking medications
  • Those with GERD

Granted, intermittent fasting can actually help alleviate some of the conditions mentioned, but you should still seek the opinion of a medical professional before you take on intermittent fasting. 

Intermittent Fasting Nutrition Basics

Good nutrition is an important part of successful intermittent fasting. Though you may experience some weight loss with IF with subpar nutrition, you won’t get the results you want, and you won’t give your body the nutrition it needs. 

Yes, some people have lost weight eating a junk food-based diet and intermittent fasting, but that’s NOT because an influx of junk is miraculously good for you when you IF, but simply because there’s a smaller window of time to eat, period and the body’s metabolic response has been bolstered by IF. So, these people who eat junk and IF are eating less with an engine that performs better, and are therefore losing weight  — but not just in the form of fat: they are losing much needed, healthy muscle mass too and not providing their bodies with the nutrients needed to function at peak.

The Importance of Muscle Mass

Healthy muscle mass can help create and sustain a more efficient metabolism and increase memory, focus and concentration. Improved muscle mass has also been shown to stimulate hormonal, enzymatic and molecular alterations which can slow and reverse chronic diseases like diabetes, heart disease and osteoporosis in men and women.

Make what you eat count…

When you have a relatively small timeframe in which to eat, you need to ensure that the foods you do consume provide your body with the nutrients it needs. That’s why loading up on Ho-hos and danishes isn’t ideal. Sure, if you cut 3000 calories of crap a day down to 1500, you will lose weight but you will not be healthy. Subsisting on these sorts of foods will not give your body all the macronutrients and micronutrients it requires to function healthfully and happily. 

Get a handle on your macros for optimal IF and tally your fat, protein and carb ratios to fit your goals. You can read our blog on maco measuring made easy. 

To learn more about how to intermittent fast with proper macronutrient intake, grab our Fast & Furiously Fit ebook. This guide is replete with more information on how to intermittent fast, including a program to help you prepare your mind and body for long-term IF success, AND 40+ amazing recipes. We’re talking tacos, burgers, ribs, brownies, ice cream, chocolates and more. Use promo code FASTED30 for $30 off. 

Just one of the recipes in our Fast & Furiously Fit ebook!

Getting Started: How to Begin Intermittent Fasting

There’s no one way to start intermittent fasting, but in our experience, there is one way that is easier than others. We’ve written about it extensively (and given you a step-by-step plan) in our ebook, but here’s a synopsis: ease your body into intermittent fasting. This may mean beginning with pushing back the time of your first meal of the day for a week or so until your body gets used to a 12 to 14 hour fast, for example. It could mean moving ahead your last meal of the day. You can pick and choose which method works best for your life and schedule, but you don’t have to throw yourself into a 16 hour fast right away. 

A 16 hour fast may be easy for people who already don’t eat after dinner, or who have a later first meal of the day, but for others, who eat before bed and as soon as they get up, 12 hours may be enough at first. Again, if you’re fueling your body properly during your eating window, getting all the nutrients you need, the challenge won’t be that you are actually hungry when you’re fasting, but that you are used to eating. 

In other words, learning how to intermittent fast boils down to breaking habits, not breaking your will. Your body will be fine--in fact, it will thrive when you intermittent fast. The difficult part may be getting your brain on board.

Remember, we got you covered! Pick up our Fast & Furiously Fit ebook for support. You can also join our Insiders Group on Facebook. Tons of your BodyRockers and trainers in this group do IF, and are always happy to answer any questions.

Intermittent Fasting Workout

Because intermittent fasting helps you lose fat, you don’t have to lean on your workouts as much to fuel fat loss. This said, working out will help you achieve the lean, sculpted look so many of us are after. 

The best intermittent fasting workouts are short, intense HIIT workouts in a fasted state. These further support fat loss, without being overly draining. BodyRock Trainer Sean Light has developed a series of workouts specifically for people who intermittent fast. It’s called Fast & Furiously Fit, and it’s one of our most popular series to date in Sweatflix

Each HIIT workout is just 23 minutes, and focuses on developing total body strength, power, speed and stability. 

For beginners or people really short on time, try BodyRock Trainer’s FFF12--a series of newbie-friendly, 12 minute intermittent fasting workouts. 

Intermittent Fasting Workout Playlist

Fast & Furiously Fit Season 1
Fast & Furiously Fit Season 2
Fast & Furiously Fit Season 3
Fast & Furiously Fit Season 4

Now you know how to intermittent fast, take the knowledge and put it into action. A healthy mind, body and life awaits.