The Beginner’s Guide to Intermittent Fasting – 2018 Update

“…But Tony the Tiger tells us that breakfast is the most important meal of the day! Grrrrrreat!”

And Tony the Tiger would NEVER lie…


This adage about breakfast has become commonplace that it’s readily and unquestionably accepted as fact:

“Want to lose weight? Make sure you start off with a healthy breakfast, so you can get that metabolism firing first thing in the morning!  “Eat breakfast like a king, lunch like a prince, and dinner like a pauper.”

“Want to lose more weight? Make sure you eat six small meals throughout the day so your metabolism stays operating at maximum capacity all day long.”

There are even studies that show those that eat earlier in the day lose more weight than those who ate later in the day or skipped a meal. [1]

So, eat breakfast to lose weight and obtain optimal health.

Case closed…right?

Maybe Not.

Maybe there’s way more to the story: what if there’s science and research that shows SKIPPING BREAKFAST (the horror! blasphemy!) is can help with optimum human performance, mental and physical health improvement, maximum muscle retention, and body fat loss?

After firmly being on “Team Breakfast” for 28 years of my life, I’ve skipped breakfast for the past 3.5 years and will most likely never go back!

I want to share with you a concept about skipping breakfast (and other meals), and how your health can benefit as a result.

I’m typing this from a secure location, just in case Tony the Tiger, The Trix Rabbit, and Toucan Sam come to beat me up.

After all, I’m going to rain on their breakfast parade with science today.

This is a topic that is controversial (which is funny – you’re just skipping a meal) as it turns a LOT of conventional wisdom on its head. This is why this article is filled with more sources and citations than the normal Nerd Fitness article.

Let’s gooooooo!

What is intermittent fasting?

This seal does Intermittent Fasting by just eating...whenever it can catch fish.

Intermittent fasting is not a diet, but rather a dieting pattern.  

In simpler terms: it’s making a conscious decision to skip certain meals on purpose.

By fasting and then feasting on purpose, intermittent fasting generally means that you consume your calories during a specific window of the day, and choose not to eat food for a larger window of time.

There are a few different ways to take advantage of intermittent fasting, which I learned about back in the day from Martin over at LeanGains, a resource specifically built around fasting and strength training:


What it is: Fasting for 16 hours and then only eating within a specific 8-hour window. For example, only eating from noon-8 PM, essentially skipping breakfast.

Some people only eat in a 6-hour window, or even a 4-hour window. This is “feasting” and “fasting” parts of your days and the most common form of Intermittent Fasting. It’s also my preferred method (3 years running).

Two examples: The top means you are skipping breakfast, the bottom means you are skipping dinner each day:

Intermittent Fasting Schedule

You can adjust this window to make it work for your life:

  • If you start eating at: 7AM, stop eating and start fasting at 3pm
  • If you start eating at: 11AM, stop eating and start fasting at 7pm
  • If you start eating at: 2PM, stop eating and start fasting at 10pm
  • If you start eating at: 6PM, stop eating and start fasting at 2AM.


Skipping two meals one day, where you are taking 24 hours off from eating. For example, eating on a normal schedule (finishing dinner at 8PM) and then not eating again until 8PM the following day.

So you would eat your normal 3 meals per day, and then occasionally pick a day to skip breakfast and lunch the next day.

If you can only do an 18 hour fast, or a 20 hour fast, or a 22 hour fast – that’s okay! Adjust with different time frames and see how your body responds.

Two examples: skipping breakfast and lunch one day of the week, and then another where you skip lunch and dinner one day, two days in a week.

How to Schedule Intermittent Fasting

Note: You can do this once a week, twice a week, or whatever works best for your life and situation.

By the way, both those weekly charts above come from our free Intermittent Fasting Starter Guide (with printable worksheets).

Most people struggle with knowing exactly when to eat and when to stop eating, and actually sticking with it. We address all of that in the Nerd Fitness Intermittent Fasting Guide you get free when you sign up for our email list in the box below:

Those are the two most popular intermittent fasting protocols, and the two we’ll be focusing on, though there are many variations of both that you can modify for yourself.

Some people eat in a 4 hour window, others do 6 or 8. Some people do 20 hour fasts or 24 hour fasts. You’ll need to experiment with them, adjust them to work for your lifestyle and goals, and see how your body responds.

Let’s first get into the science here behind Intermittent Fasting and why you should consider it!

How does intermittent fasting work?


Now, you might be thinking: “okay, so by skipping a meal, I will eat less than I normally eat on average (2 meals instead of 3), and thus I will lose weight, right?”

Yes, by cutting out an entire meal each day, you are consuming fewer calories per week – even if your two meals per day are slightly bigger than before. Overall, you’re still consuming fewer calories per day. This is highlighted in a recent JAMA study[b] in which both calorie restricted dieters and intermittent fasters lost similar amounts of weight over a year period.

That doesn’t tell the FULL story, as we already know that not all calories are created equal,  and that the timing of meals can also influence how your body reacts.

Intermittent Fasting can also help because your body operates differently when “feasting” compared to when “fasting”:

When you eat a meal, your body spends a few hours processing that food, burning what it can from what you just consumed.  Because it has all of this readily-available, easy to burn energy (thanks to the food you ate), your body will choose to use that as energy rather than the fat you have stored.  This is especially true if you just consumed carbohydrates/sugar, as your body prefers to burn sugar as energy before any other source.

During the “fasted state” (the hours in which your body is not consuming or digesting any food) your body doesn’t have a recently consumed meal to use as energy, so it is more likely to pull from the fat stored in your body as it’s the only energy source readily available.

Burning fat = win.

The same goes for working out in a “fasted” state.  Without a ready supply of glucose and glycogen to pull from (which has been depleted over the course of your fasted state, and hasn’t yet been replenished with a pre-workout meal), your body is forced to adapt and pull from the only source of energy available to it: the fat stored in your cells.

Why does this work?  Our bodies react to energy consumption (eating food) with insulin production. The more sensitive your body is to insulin, the more likely you’ll be to use the food you consume efficiently, and your body is most sensitive to insulin following a period of fasting [4].

These changes to insulin production and and sensitivity can help lead to weight loss [2] and muscle creation [3].

Next: Your glycogen (a starch stored in your muscles and liver that your body can burn as fuel when necessary) is depleted during sleep (aka during fasting), and will be depleted even further during training, which can lead to increased insulin sensitivity.

This means that a meal following your workout will be stored most efficiently.

During that period, the food you consumed will be used in a few ways: converted to glycogen and stored up in your muscles or burned as energy immediately to help with the recovery process, with minimal amounts stored as fat.

Compare this to a regular day (no intermittent fasting):  With insulin sensitivity at normal levels, the carbs and foods consumed will see full glycogen stores and enough glucose in the bloodstream, and thus be more likely to get stored as fat.

Not only that, but growth hormone is increased during fasted states (both during sleep [5]and after a period of fasting). Combine this  increased growth hormone secretion:[6], the decrease in insulin production (and thus increase in insulin sensitivity [7]), and you’re essentially priming your body for muscle growth and fat loss with intermittent fasting.

The less science-y version: Intermittent fasting can help teach your body to use the food it consumes more efficiently, and your body can learn to burn fat as fuel when you deprive it of new calories to constantly pull from (if you eat all day long).

TL/DR: For many different physiological reasons, fasting can help promote weight loss and muscle building when done properly.

I know this Intermittent Fasting stuff can be overwhelming, so I created a free guide and worksheet to help you get started on the right foot. 

Sign up for the free Intermittent Fasting Starter Guide and Worksheets when you put your email in the box below:

But why does every health book say “6 small meals?”

Small plate of sausages - eat it on YOUR schedule

There are a few main reasons why diet books recommend six small meals:

1) When you eat a meal, your body does have to burn extra calories [8] just to process that meal.  So, the theory is that if you eat all day long with small meals, your body is constantly burning extra calories and your metabolism is firing at optimal capacity, right? Well, that’s not true.

Whether you eat 2000 calories spread out throughout the day, or 2000 calories in a small window, your body will burn the same number of calories processing the food [9]. So, the whole “keep your metabolism firing at optimum capacity by always eating” sounds good in principle, but reality tells a different story.

2) When you eat smaller meals, you might be less likely to overeat during your regular meals. I can definitely see some truth here, especially for people who struggle with portion control or don’t know how much food they should be eating.

However, once you educate yourself and take control of your eating, some might find that eating six times a day is very prohibitive and requires a lot of effort. I know I do. Also, because you’re eating six small meals, I’d argue that you probably never feel “full,” and you might be MORE likely to eat extra calories during each snack.

Although grounded in seemingly logical principles, the “six meals a day” doesn’t work for the reason you think it would (#1), and generally only works for people who struggle with portion control (#2).

If we think back to caveman days, we’d have been in serious trouble as a species if we had to eat every three hours. Do you think Joe Caveman pulled out his pocket sundial six times a day to consume his equally portioned meals?

Hell no! He ate when he could, endured and dealt with long periods of NOT eating (no refrigeration or food storage) and his body adapted to still function optimally enough to still go out and catch new food.

A recent study (written about in the NYT, highlighted by LeanGains) has done a great job of challenging the “six-meals-a-day” technique for weight loss [10]:

There were [no statistical] differences between the low- and high- [meal frequency] groups for adiposity indices, appetite measurements or gut peptides (peptide YY and ghrelin) either before or after the intervention. We conclude that increasing meal frequency does not promote greater body weight loss under the conditions described in the present study.

Factor in the potential physiological benefits listed in the previous section, and you got yourself some damn good science-backed evidence to consider trying Intermittent Fasting if you want to decrease body fat and build muscle.

Why intermittent fasting?

Intermittent Fasting Apple Plate

Now that we’re through a lot of the science stuff, let’s get into the reality of situation: why should you consider Intermittent Fasting?

Because it can work for your goals. Although we know that not all calories are created equal, caloric restriction plays a central role in weight loss. When you fast, you are also making it easier to restrict your total caloric intake over the course of the week, which can lead to consistent weight loss and maintenance.

Because it simplifies your day. Rather than having to prepare, pack, eat, and time your meals every 2-3 hours, you simply skip a meal or two and only worry about eating food in your eating window. It’s one less decision you have to make every day. It could allow you to enjoy bigger portioned meals (thus making your tastebuds and stomach satiated) and STILL eat fewer calories on average.

It requires less time (and potentially less money). Rather than having to prepare or purchase three to six meals a day, you only need to prepare two meals. Instead of stopping what you’re doing six times a day to eat, you simply only have to stop to eat twice. Rather than having to do the dishes six times, you only have to do them twice. Rather than having to purchase six meals a day, you only need to purchase two.

It promotes stronger insulin sensitivity and increased growth hormone secretion, two keys for weight loss and muscle gain.  Intermittent fasting helps you create a double whammy for weight loss and building a solid physique.

It can level up your brain, including positively counteracting conditions like Parkinson’s, Alzheimer’s, and dementia. As explained here in this TEDx talk by Mark Mattson, Professor at Johns Hopkins University and Chief of the Laboratory of Neurosciences at the National Institute on Aging fasting is grounded in serious research and more studies are coming out showing the benefits:

Plus, Wolverine does it:

And so does Boy George (who apparently reads Nerd Fitness!)

What are the drawbacks with intermittent fasting?

Fasting can leave you HUNGRY.

In my own experimentation over the past four years, I have found very few negative side effects with Intermittent Fasting. 

The biggest concern most people have is that Intermittent Fasting will lead to lower energy, focus, and the “holy crap I am hungry” feeling during the fasting period and ruin them. People are concerned that they will spend all morning being miserable because they haven’t consumed any food, and thus will be miserable at work and ineffective at whatever task it is they are working on.

The following are my thoughts and experiences, and your results may vary:

Yes, the initial transition from EATING ALL THE TIME, to intermittent fasting MIGHT be a bit of a jolt to your system; it was for me. However, once I got through the transition after a few days, my body quickly adapted and learned to function just as well only eating a few times a day.

Although I fast for 16 hours per day with no issues, the following might help assuage your fears that skipping breakfast will cause your body to eat itself and your brain to implode:

After 48-hours of fasting in a recent study [12], “cognitive performance, activity, sleep, and mood are not adversely affected in healthy humans by two days of calorie-deprivation.” You’ll be fasting for less time than that.

“So why do I feel grouchy and lethargic when I skip breakfast?” 

In this nerd’s humble opinion, a good portion of the grumpiness is a result of past eating habits. If you eat every three hours normally,and normally eat as soon as you wake up, your body will start get to get hungry every three hours as it learns and becomes used to expecting (and receiving) food every three hours.

If you eat breakfast every morning, your body is expecting to wake up and eat food.

Once you retrain your body to NOT expect food all day every day (or first thing in the morning), these side-effects become less of an issue. In addition, ghrelin (a hormone that makes you hungry [13]), is actually lowest in the mornings and decreases after a few hours of not eating too. The hunger pains will naturally pass!

Personally, I found this grumpiness subsided after a few days and now my mornings actually energize me.

It’s important to understand that Intermittent Fasting is NOT a cure-all panacea. Don’t delude yourself into thinking that if you skip breakfast and then eat 4,000 calories of candy bars for lunch and dinner that you will lose weight.

If you have an addictive relationship with food and you struggle with portion control, track your calorie intake in your meals to make sure you’re not overeating. If you skip breakfast, you might be so hungry from this that you OVEREAT for lunch and this can lead to weight gain. Again, the important thing here is that with intermittent fasting you’re eating fewer calories than normal because you’re skipping a meal every day.

Think about it in caveman terms again.  We certainly found ways to survive during periods of feast and famine, and that remains true today. imagine if you needed to eat in order to be active and alert: what would hungry cavemen do?

They would go find food, and that probably required a ton of effort. It actually takes our bodies about 84 hours of fasting [14] before our glucose levels are adversely affected. As we’re talking about small fasts (16-24 hour periods), this doesn’t concern us.

AN IMPORTANT CAVEAT: Intermittent Fasting can be more complex for people who have issues with blood sugar regulation, suffer from hypoglycemia, have diabetes, etc. If you fit into this category, check with your doctor or dietitian before adjusting your eating schedule. It also affects women differently (there’s a whole section dedicated to that below)

Can I build muscle and gain weight while intermittent fasting?

Intermittent Fasting Encourages Hypertrophy!

You’re damn right you can!

In fact, I have been intermittent fasting for the past three years while building muscle and decreasing my body fat percentage:

Intermittent Fasting Helped Steve!

I still eat roughly the same number of calories I was consuming before, but instead of eating all damn day long, I condense all of my calorie consumption into an eight hour window.

  • 11 AM Work out with heavy strength training in a fasted state.
  • 12 PM Immediately consume 1/2 of my calories for the day (a regular whole-food meal, followed by a calorie-dense homemade shake.)
  • 7 PM Consume the second portion of my calories for the day in a big dinner.
  • 8 PM – 12 PM the next day: Fast for 16 hours.

In a different method, my friend Nate Green packed on a crazy amount of muscle while fasting for a full 24 hours on Sundays – so it is possible. [15]

I’m not kidding when I say this has revolutionized how I look at muscle building and fat loss.

Ultimately, this method flies in the face of the typical “bulk and cut” techniques of overeating to build muscle (along with adding a lot of fat) before cutting calories to lose fat (along with some muscle) and settling down at a higher weight.

I prefer this method to the bulk-and-cut technique for a few reasons:

  • There’s far less of a crazy swing to your weight. If you are putting on 30 pounds and then cutting 25 to gain 5 lbs of muscle, your body is going through drastic swings of body mass. Your clothes will fit differently, you’ll have different levels of definition, and your body will wonder what the hell is going on.
  • You’re consuming less food and thus spending less money. Rather than overeating to put on 1 pound of muscle and 4 pounds of fat in a week or two, you’re aiming to eat exactly enough to put on 1 pound of muscle without adding much fat on top of it.  Yeah, it’s a delicate balance, but there’s far less swing involved. You are just slowly, steadily, and consistently building muscle and strength over many months.
  • There’s never a need to get “vacation-ready”: we all want to look good naked, right?  When you are just adding muscle, you don’t need to worry about getting your body ready before by drastically altering your diet (going on a miserable crash diet for a month). [16]
  • You can make small adjustments and stay on target. Keep your body fat percentage low, build strength and muscle, and if you happen to notice your body fat creeping up, cut back on the carbs. Within two weeks you should be back at your preferred body fat percentage and can continue the muscle building process.

A note on BCAA consumption. Martin from LeanGains [17] recommends consuming Branched Chain Amino Acids (BCAA’s) as a supplement with regards to fasted training to aid your muscles through your workout.

Personally, I used BCAAs for about 6-8 months during my initial start with fasted training (consuming them before training), though haven’t used them in the past 2+ years. I did NOT notice any adverse affects to not taking them with regards to my performance. Your value may vary!

Remember that Intermittent Fasting is a piece of the puzzle.

We have our online course, The Nerd Fitness Academy, that digs into the rest of the puzzle: how to properly strength train, how to structure your diet, and build a solid mental attitude with regards to getting in great shape.

You can combine this information with Intermittent Fasting to turbocharge your results! If you’re curious about how to get started and worrying about following through, check out free Intermittent Fasting Start Guide with printable worksheets to stay on track when you join the NF email list below:

Does intermittent fasting have different effects on men and women?

Run fast - on a fast

The quick answer is: “yes, Intermittent Fasting can affect men and women differently.” Anecdotally, I know many women that swear by Intermittent Fasting, while others have had adverse effects. Let’s dig into the science and studies.

A recent PubMed summary concluded that “fasting can be prescribed as a safe medical intervention as well as a lifestyle regimen which can improve women’s health in many folds [18].

Now, in that extract, many of the studies cited are focused on specifically calorie restriction (and not just fasting), and they also say that “future studies should address this gap by designing medically supervised fasting techniques to extract better evidence.”

Digging into the PubMed Archives brought me to the following conclusions [a]:

One small study (with 8 men and 8 women, all non-obese) resulted in the following: “Glucose response to a meal was slightly impaired in women after 3 weeks of treatment, but insulin response was unchanged. Men had no change in glucose response and a significant reduction in insulin response.”[19]

Another small study (8 women) studied the effects on their menstrual cycles after a 72 hour fast – which is significantly longer than any fast recommended in this article: “in spite of profound metabolic changes, a 72-hour fast during the follicular phase does not affect the menstrual cycle of normal cycling women.” [20].

Yet another study tracked 11 women with 72 hour fasts (again, longer than we’d recommend) and it found that “Fasting in women elicited expected metabolic responses – included increased cortisol (a stress hormone) – and apparently advanced the central circadian clock (which can throw off sleeping patterns). [21].

Those studies above, in working with small sample sizes, and different types of fasting than recommended here, would lead me to believe that fasting affects men and women differently, and that many of the weight loss benefits associated with intermittent fasting (that affect insulin and glucose responses) work positively for men and negatively for women.

There are also a series of articles[22] out there that dig into the potential reproductive health issues, stress challenges, induction of early-menopause [23] associated with fasting (and calorie restriction) for women.

Precision Nutrition recommends not attempting Intermittent Fasting as a woman if:

The challenge associated with all of this is that there aren’t enough long-term studies, with large enough sample sizes, specifically targeting female humans, with relation to the different types of Intermittent Fasting.

ALL OF THIS TO SAY: It does appear that men and women will have different experiences with intermittent fasting; we’re all unique snowflakes (yep, especially you), and your body will be affected by intermittent fasting differently than the person next to you.

There is enough evidence as cited in the articles and studies above that would give me pause to recommend Intermittent Fasting for women, especially if you are considering getting pregnant in the near term.

If you are looking to attempt intermittent fasting for weight loss reasons, my research has shown me that Intermittent Fasting could be less effective for women than men with regards to weight loss, and thus you would be wise to keep your efforts elsewhere:

  • Focusing on the total calories and quality of your food (here’s how to eat better).
  • Start exercising regularly!
  • Make sure you are getting enough sleep.

Now, if you’ve read the above warnings, you are still curious about Intermittent Fasting, and you want to give it a try as a female, that is your choice! You know your body best.

So, get blood work done, speak with your doctor and get a check-up. Give intermittent fasting a shot, track your results, and see how your body/blood work changes as a result of Intermittent Fasting and decide if it’s right for you.

Your milage may vary, so speak with a doctor or find a doctor versed in intermittent fasting protocols and treat it like an experiment on yourself!

Questions about intermittent fasting

Eat the right foods when practicing intermittent fasting!

1) “Won’t I get really hungry?”  

As explained above, this can be a result of the habits you have built for your body. If you are constantly eating or always eat the same time of day, your body can actually learn to prepare itself for food by beginning the process of insulin production and preparation for food.

After a brief adjustment period, your body can adapt to the fact that it’s only eating a few times a day. The more overweight you are, and the more often you eat, the more of an initial struggle this might be.

Remember, your body’s physical and cognitive abilities aren’t diminished as a result of fasting.[24].

2) “Where will I get my energy for my workouts? Won’t I be exhausted and not be able to complete my workouts if fasting?” 

This was a major concern of mine as well, but the research says otherwise: “Training with limited carbohydrate availability can stimulate adaptations in muscle cells to facilitate energy production via fat oxidation.”[25].

In other words, when you train in a fasted state, your body can get better at burning fat for energy when there are no carbs to pull from!

I’ll share some of my experiences, now doing heavy strength training for 3 years in a fasted state: For my first “fasted” workout or two after starting an IF protocol, it was very weird to not eat before training. However, after a few sessions, I learned that my body could certainly function (and even thrive) during my training sessions despite not eating a pre-workout meal.

Here I am pulling 385 lbs. at 175 BW after a 16 hour fast:

3) “I like the idea of fasted training, but I work a regular 9-5 or a night shift and can’t train at 11AM like you do. What am I supposed to do?”

Depending on your training schedule, lifestyle, and goals, go back to the portion above where I talk about the 16/8 protocol and simply adjust your hours of fasting and feasting. LeanGains digs into various options here, but here is really what you need to know:

  • Don’t overthink this. If you can’t train until 5pm, that’s okay. Consume a small meal for lunch, or shift your Intermittent Fasting window to eat all of your meals in the 8 hours post workout. Better to do that than abandon it as a lost cause and have 0% compliance.
  • If you are an elite athlete, speak with a coach or nutritionist about your specific concerns and expectations. Otherwise, make intermittent fasting work for you Consider trying the 24-hour protocol below instead of the 16/8 protocol.
  • If you train later in the day (say, 7pm) but break your fast before training (aka Lunch), make it a smaller meal focused around fats and protein – which should be a solid goal even if you aren’t Intermittent Fasting! Try to time your carb and big meal consumption to happen AFTER your workout.
  • If you exercise BEFORE work, but then don’t eat until lunchtime: consider a protein supplement immediately after your workout, or simply wait until lunch to start eating. See how your body responds and adjust accordingly.

Do what you can, and don’t psyche yourself out! Get started and adjust along the way.

“Won’t fasting cause muscle loss?”  

Another big concern of mine, but it turns out this fear was unfounded. We’ve been told by the supplement industry that we need to consume 30 g of protein every few hours, as that’s the most amount of protein our body can process at a time. Along with that, we’ve been told that if we don’t eat protein every few hours, our body’s muscle will start to break down to be burned as energy.

Again, NOT TRUE! Our bodies are quite adept at preserving muscle even when fasting [25], and it turns out that protein absorption by our body can take place over many many many hours. Protein consumed in a shorter period of time has no difference on the body compared to protein spread throughout the day.    

4) “What about my body going into starvation mode from not eating?” 

Now, the thought process here is that when we don’t feed ourselves, our bodies assume calories aren’t available and thus choose to store more calories than burning them, eliminating the benefits of weight loss with fasting. Fortunately, this is NOT true.

Starvation mode is real, but it is significantly overblown and sensationalized these days. It takes a dramatic amount of starvation, for a long time, before your body kicks into “starvation mode”. We’re talking about 24 hour or 16 hour fasts here, and starvation mode takes significantly longer than that.[26]

In other words: starvation mode should not be factoring into your decision here.

5) How much should I eat while intermittent fasting? 

Simple: Eat for your goals! If your goal is weight loss, you still need to consume fewer calories than you burn every day to lose weight. If your goal is bulking up, you’ll need to consume more calories than you burn every day. Intermittent Fasting isn’t a cure-all, it’s a PART of the puzzle.

To start, begin intermittent fasting and eat your normal sized meals and track your weight and performance. If you are losing weight and happy with the progress, keep doing what you’re doing! If you are NOT losing weight, you could be eating too much – track your calories for a week, and then target a 10% reduction in calories and continue.

If you’re worried about all of this stuff, or aren’t sure when to eat and stop eating, check out our free IF Guide (sign up in the box below) that tackles these questions and makes it easy for you to get started and track your first month doing Intermittent Fasting!

Tips and tricks about Fasting 

hungry ant

Don’t freak out! Stop wondering: “can I fast 15 hours instead of 16?” or “what if I eat an apple during my fasted period, will that ruin everything?”  Relax. Your body is a complex piece of machinery and learns to adapt. Everything is not as cut and dry as you think.

If you want to eat breakfast one day but not another, that’s okay. If you are going for optimal aesthetic or athletic performance, I can see the need to be more rigid in your discipline, but otherwise…freaking chill out and don’t stress over minutiae! Don’t let perfect be the enemy of good.

Consider fasted walks in the morning. I found these to be very helpful in reducing body fat, and also gave my day a great start to clear my mind and prepare for the day. Simply wake up and go for a mile walk. Maybe you could even start walking to Mordor?

Listen to your body during workouts. If you get light headed, make sure you are consuming enough water. If you notice a significant drop in performance, make sure you are eating enough calories (especially fats and protein) during your feasting window. And if you feel severely “off,” pause your workout. Give yourself permission to EASE into intermittent fasting and fasted workouts. This is especially true if you are an endurance athlete.

Expect funny looks if you spend a lot of mornings with breakfast eaters.  A few weeks back I had a number of friends staying with me, and they were all completely dumbfounded when I told them I didn’t eat breakfast anymore. I tried to explain it to them but received a bunch of blank stares. Breakfast has become so enGRAINed (zing!) in our culture that NOT eating it sounds crazy.  You will get weird looks from those around you…embrace it. I still go to brunch or sit with friends, I just drink black coffee and enjoy conversation.

Stay busy.  If you are just sitting around thinking about how hungry you are, you’ll be more likely to struggle with this. For that reason, I time my fasting periods for maximum efficiency and minimal discomfort:

  • My first few hours of fasting come after consuming a MONSTER meal, where the last thing I want to think about is eating.
  • When I’m sleeping: 8 of my 16 hours are occupied by sleeping.  Tough to feel hungry when I’m dreaming about becoming a Jedi.
  • When I’m busy: After waking up, 12 hours of my fasting is already done.  I spend three hours doing my best work (while drinking a cup of black coffee), and then comes my final hour of fasting: training.

Zero-calorie beverages are okay.  I drink green tea in the morning for my caffeine kick while writing. If you want to drink water, black coffee, or tea during your fasted period, that’s okay.  Remember, don’t overthink it – keep things simple! Dr. Rhonda Patrick over at FoundMyFitness believes that a fast should stop at the first consumption of anything other than water, so experiment yourself and see how your body responds.

If you want to put milk in your coffee, or drink diet soda occasionally while fasting, I’m not going to stop you. Remember, we’re going for consistency and habit-building here – if milk or cream in your coffee makes life worth living, don’t deprive yourself.

There are MUCH bigger fish to fry with regards to getting healthy than a few calories here and there during a fast. 80% adherence that you stick with for a year is better than 100% adherence that you abandon after a month because it was too restrictive. If you’re trying to get to a minimum bodyfat percentage, you’ll need to be more strict – until then, however, do what allows you to stay compliant!

Track your results, listen to your body:  

  • Concerned about losing muscle mass?  Keep track of your strength training routines and see if you are getting stronger.
  • Buy a cheap set of body fat calipers and keep track of your body fat composition.
  • Track your calories, and see how your body changes when eating the same amount of food, but condensed into a certain window.
  • Sign up for the NF Email list in the box below and get your free Intermittent Fasting Starter Guide and Worksheets to track your progress.

Everybody will react to intermittent fasting differently; I can’t tell you how your body will react.  It’s up to you to listen to your body and see how making these adjustments change your body.

Don’t expect miracles.  Yes, intermittent fasting can potentially help you lose weight, increase insulin sensitivity and growth hormone secretion (all good things), but it is only ONE factor in hundreds that will determine your body composition and overall health.  Don’t expect to drop to 8% body fat and get ripped just by skipping breakfast.

We cover all of this in the NF Academy, but you need to focus on building healthy habits, eating better foods, and getting stronger.

This is just one tool that can contribute to your success.

To sum it all up

Intermittent fasting can potentially have some very positive benefits for somebody trying to lose weight or gain lean body mass.

Intermittent fasting can potentially have some very positive benefits for somebody trying to lose weight or gain lean body mass.

Men and women will tend to have different results, just like each individual person will have different results.  The ONLY way to find out is with self-experimentation.

There are multiple ways to “do” intermittent fasting:

  • Fast and feast regularly: Fast for a certain number of hours, then consume all calories within a certain number of hours.
  • Eat normally, then fast 1-2x a week: Consume your normal meals every day, then pick one or two days a week where you fast for 24 hours.  Eat your last meal Sunday night, and then don’t eat again until dinner the following day.
  • Fast occasionally: probably the easiest method for the person who wants to do the least amount of work. Simply skip a meal whenever it’s convenient. On the road? Skip breakfast.  Busy day at work? Skip lunch.  Eat poorly all day Saturday?  Make your first meal of the day dinner on Sunday.

After that, get started. Take photos, step on the scale, and track your progress for the next month. See how your body responds. See how your physique changes. See how your workouts change.

And then decide if it’s something you want to keep doing!

4 years later, I have no plans on going back to eating breakfast. Sorry General Mills and Dr. Kellogg!

I’d love to hear from you:

  • What are your questions with intermittent fasting?  
  • What are your concerns?
  • Have you tried intermittent fasting?
  • Have you had success with it, either with muscle gain or weight loss?

Thanks for leaving your comment, I’m excited to get the conversation started.


PS: You just read 6,700 words, and for that, I applaud you. If you’ve come this far, maybe you’re willing to go a little further?

I’ve found a lot of people struggle with knowing exactly when to eat and not eat, and keeping track of their fast and feast windows, so I made a Intermittent Fasting Starter Guide that tackles all of those challenges.

Sign up in the box below and get it free. 


Photo Source: seal mouth, tony the tiger, anatomy, cog, small plates, apples, fridge, ant, boy girl, kiwi

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  • Karli Giles

    So I’m going to try the 16/8 and for the most part I sleep a majority of those hours, but I’m trying to regulate my sleep to just a flatbed 8 hours instead of longer. My question is in the 8 hour period what should one eat and how much? Am I supposed to stay within a daily caloric intake specific to my height, weight and age? That’s the last thing I’m trying to sort out before starting.

  • RomertL

    Trying this now, eating everything within about 3-4 hour window after training. First day now

  • Rosie R

    This was a great informative piece! Thank you for this! I’m wondering though- can you switch it around by skipping dinner starting from 16:30-8:30? I’m assuming that it would probably work the same way. I’m from South Africa so our days start quite early and end the same way as well. And nighttime doesn’t usually require much activity or calories.

  • Dawn Wheatley

    Im a 35 year old female and have gained alot of weight in a short period of time i need to get healthy and get healthy quick i think this is something i will try but in my time period of eating what do i eat and how much i love green tea i drink alot of it what about diet cokes and im a beginner on exercise what exercises are good to do at home with a two year old i need help bad

  • Dawn Wheatley

    May i ask what you ate and how much through the window

  • Dawn Wheatley

    I need help i dont know what or how much to eat during the window or what exercises to do with a 2 year old at home please any advise

  • What’s wrong with breakfast? You can still fast after breakfast.

  • I wrote an ebook on intermittent fasting. if you’d like to find out how you can get it, please write me at

  • Mohamed Mourad

    Can the meal i eat after fasting be like the cheat meal i get in the six meal diet plan or it have to be more healthy like grilled chicken and other?

  • Liam Brown

    Can i fast 4pm 8am one week then then 8pm till 12 the week after alternating every week due to shift work. would this mess metabolism up?

  • Gwyneviere

    I think homemade bone broth would be a much better option than miso but that’s just my opinion. Making your own bone both is very easy, and so good for you!

  • emily kalinda

    I just started fasting for 16 hours my only concern is not eating enough but I do try to stick to healthy meals I haven’t lost any weight yet, but I am hoping to keep this up

  • Amy

    Hey Dawn! I have been IF for over 2 weeks. I have a 4yr old and a 1yr old. Today is my first 24hr fast and it’s going well. I’m not really concerned with how much I eat in the window. My typical day is a protein shake around 12 with lunch soon after, a protein and a veggie. Then I usually get hungry about 4 and make another protein shake and dinner soon after, a protein, veggie and fruit. I don’t stick to this 100%, but that’s what happens most days if we are at home. I haven’t added exercise back in (I’ve always been a gym-goer) and will likely be adding in something soon-just not sure what I’m going to choose. It is hard at first to feed your kid(s) and not eat! But, I have gotten used to it and it doesn’t bug me so badly anymore. We are all eating healthier since I started!

  • Thank you for the informative article! I had some interesting experiences with fasting. A few years back I had adrenal failure and my immune system was so weak that I unfortunately got a rare form of shingles referred to as Ramsay Hunt Syndrome. Basically you get shingles “inside” your face (the sores associated with shingles were in the ear, in the eye and down my throat) and it leads to paralyses of the facial nerves. My hair fell out, my nails stopped growing for two years and it took three months before any movement in my face returned. The pain was unbearable. I had this horrible disease in 2004 on the right side of my face and
    again in 2011 on the left side. With shingles the symptoms never really goes away. When ever I have a drop in my immune system – even with a common cold – the pain in my facial nerves would return. Through help of informative articles like yours I started experimenting with different healthy habits to maintain a healthy immune system. I was very overweight and unfit. I started with an exercise routine and healthy eating program. But as soon as the weight loss was to fast my immune system would weaken and the pain would return. I was tired all the time, struggled to concentrate and even had challenges with my memory. I could drink no coffee or any other caffeine loaded drinks because of the adrenal failure so that sporadic energy boost was out of the question. I then started experimenting with fasting. And now, a few years down the road, I am almost three dress sizes smaller, I am graduating next week with a second degree, I can concentrate, I have physical endurance and I rarely have the pain in my facial nerves. I eat in a 8 hour window and fast for the rest. It has been a blessing to experience this road to recovery and find the wisdom and courage to do this. The Lord as truly been my Guide.

  • lanie

    Very interesting and i want to give a try.. i have issues on my body i can loose weight easily but my mid section remains big and looks bloated I run 3 times a week , can anybody help me

  • Zachary Willliams

    If you want to gain weight its simple increase calories by 300-500 hundred. If you plateu on muscle gain you need to life heavier weights. Do not lift the same thing for months and expect you do look bigger and become stronger. You need to lift heavier to build strength and strength=muscle and definition. Fasting works amazingly. If will help define your muscles but you gotta build muscle first otherwise your not going to see the results you want.

  • Robert

    Thanks for posting this. I thoroughly enjoyed reading every bit of it. During fasting period, what are your thoughts on adding coconut oil to black coffee? I realize I’m going further down the rabbit hole asking this, but am very interested in giving this a shot.

  • Gary Fischer

    I am so confused on a simple question regarding the strictness of a 12 hour (or 14 hour…or what ever time period) fast. Lots of conflicting information. Some of the numerous articles say coffee or tea during this 12 hour fasting period is fine. Others say that tea or coffee will yet interrupt the fasting cycle, affecting metabolism of the fast and should be avoided.

    Any definitive information on yes or no to coffee or tea?

  • Ben Stark

    Jason Fung is the expert on this and he has written pretty clearly that you are in control. If you are really, really, really hungry or feeling not well, eat something. I typically fast 16 hours per days, but some days, I feel pretty bad and a little bit of fat may help feel better. I have still have lost weight. I drink coffee every day. Doing well.

  • Sean Murphy

    8 on and 16 off, Is that every day or just certain days of the week?

  • AlekHartzog

    It can be whatever structure works for you – maybe you only do it M-F, or do it all 7 days if that helps you keep the habit!

  • Kate Semple

    I used to do IF when I worked my old job where I would be driving from patient to patient all day and hated eating in my car. I ate a big paleo dinner at 5 and then a 2nd similar portion dinner after my son went to be at 7:30. I just drank black coffee and water through the day. I found it easy to stay lean and I didn’t feel hungry all day because that’s what I was used to doing. I found though I felt freezing cold all day long in the winter. I don’t IF any more because I have small children who eat all the time and don’t like to have them do one thing going while I do another. Feels hypocritical.

  • Thank you for including an extensive section for women. Most IF articles I’ve read either don’t mention the difference for women at all or brush it off with a single comment and no explanation. I appreciate the acknowledgement that IF is not for everyone.

  • Jamie Collier

    I am curious how Intermittent fasting effects endurance and being able to perform at a high energy level for 6-8 hour lengths of times???

  • Jeffrey Schultz

    I have a question related to IF I’m hoping people here can answer. I like to work out in the morning (0700ish) and usually have breakfast immediately following that workout. If I start with IF and don’t want to change my workout time, should I just work out as normal and have a meal at noon, or do I need something after that workout? I’d rather not break the fast right after that workout and then have to stop eating at 4 in the afternoon. Thanks.

  • Liz

    I enjoy IF, but I don’t skip any meals. I just pack them all into my 8 hour window (generally from 9 to 5) and then workout later at night.

  • Tony Langdon

    Very interesting article that turns conventional wisdom on its head, but at the same time it does make some sense. At this point in time, it’s food for thought (pardon the pun 😉 ).. I’m already in a good place, meeting my physical goals, so I don’t need to consider anything drastic, but I still gather information like this for future consideration. There might be a time when I’m ready to give it a try for whatever reason.

  • Mindy Neal

    I stop eating earlier in the day – somewhere between 4pm and 6pm, usually around 4:30, depending on the day, and track my fast with the goal of 13 hours of fasting. It works better for me because I’m not a night person. 🙂

  • Kristin

    This was a great article. I’ve just started researching Intermittent Fasting and have a few questions. If you’re opting to make your 6-8 hour window of eating span from breakfast (say, 9-5), when is the best time to exercise? Also, are you eating two big meals, or snacks between, or what? I’m not finding much clarity on that in my research so far. Thank you!!!

  • Ryan Witt

    I’ll be working 7am-3:30pm and I’m wondering if this schedule I have in mind is okay to reap the benefits of IF.

    9pm-12pm is FASTING

    12pm – small lunch (25-35% of calories)
    5pm – Exercise (Usually 90 minutes of Tennis or Soccer)
    7pm – big dinner(65-75% of calories)

    Just trying to figure out the easiest way to incorporate fasting into my weekly life.


  • Ryan Witt

    so you don’t eat after working out? Has this been okay for your progress?

  • Yoon Soxx

    Is vodka soda or whisky soda considered a zero cal drink that can be consumed during fasting? Im actually serious, i consider socialising an important part of my life and drinks are involved most nights.

  • Igor

    I believe that this concept is good. I remember sometimes when I skipped breakfast that I felt good. We burden ourselves with food too much. Thing that helps with fasting are daily obligations, like work or other things. Than this fasting is much easier. You just do not think about breakfast early in the morning, but eat when you get a chance later in the day. And without feeling blame for not eating breakfast 🙂
    I remember feeling exceptionally good on those days that I do not eat breakfast due to my work. I am much sharper, active. I think that life without ever feeling hungry makes us slower, without edge, and never gives us chance to feel those special feelings of agility and liveliness.
    All in all, I believe in this concept and I will give it a proper try.

  • Wayde Lawler

    Alcohol has 7 calories per gram so I don’t think it would count. One drink probably wouldn’t be a huge deal though.

  • Igor

    Yes. Better vodka or whisky soda than whole meal. Perfectionism is what kills good ideas in very start. Use common sense.

  • Sam Liu Liang

    I got a very good question and everyone that I have personally asked had ignored the question. Can Intermediate fasting stop you from getting taller?

  • O’Quaria Harris

    What if I don’t consume enough calories within my 8 hours??

  • Meh

    How many layers of clothing do you need to wear for looking bigger in the “after” photo? Asking for a friend. 😛

  • yelahneb

    Been on this for 60 days and loving it. I’ve gone from 240 to 220 as of today. I feel more clear-headed and active than I have in ages. Old clothes fit again – a huge morale post. Exercising everyday. Thank you for this wisdom!

  • Kathy Charest

    This was a great article. My husband and I have been doing Intermittent fasting for a few weeks, but we have been incorporating the ketogenic diet as well and decided a couple of days ago that it was WAY too restrictive and we would rather just do pretty much as you mentioned above (eating lower, but healthy carbs, moderate protein, healthy fats, not going overboard). We choose to not eat sugar except on very rare occasions, so that’s not a problem.
    Our biggest question (more for him than me) is can he snack between meals? Like… not on bad things, but some celery and PB, or a fruit etc…. or will this increase in insulin be an issue?

  • Kathy Charest

    Hi LauraBeth,
    Did you do anything like the ketogenic diet? Or has this worked for you eating just healthy balanced meals?

  • Hello. I wrote an actual EBOOK on Intermittent Fasting. I am not able to eat ketogenic because the low carb count results in my blood sugar dropping too low to a point that I almost go into a panic attack, feeling like I am dying. I can tell you that I eat breakfast as close to 11 AM as possible and it’s usually eggs n bacon or flax/chia cereal or oatmeal waffles and then I have a piece of fruit or a string cheese for a snack. Lunch I eat leftovers or 1/2 to 1 sandwich on healthy bread, a bit of mayo or some other homemade gluten free something, Dinner is usually a meat and veg and small carb if I’m hungry for it. So far, I’m happy with just doing IF.

  • Paula, I could not fast 24 hours because of the low blood sugar. How on earth do you manage that without feeling shaky, irritable and deathly ill?

  • I walk as often as I can. Can’t exercise due to asthma

  • I’d love to know how it works for you!

  • Great summary on intermittent fasting, I’ve been doing an 16/8 fast for many years and it really works great for me. Lots of energy and I have able to stay relatively lean throughout the year.

  • Paula Buchanan

    Laura, I’m not really sure. I don’t feel that I have blood sugar issues because of my adrenals, I have just always read that, so I wanted to state that it IS a possibility. I sometimes get a slight headache, but that is usually like it I don’t drink much water. Staying hydrated helps tremendously. An FYI: I always start my fast after dinner, so when I get up in the morning, I am halfway done. Then just skip breakfast and lunch and eat dinner that night. I’m sorry you cannot do it Laura, as this has been the easiest weight-loss regime I’ve ever done, and I know I will be able to maintain with this method. I also feel my results are better if I just have meals, no snacks. Not even saving part of a meal for a snack later. It just doesn’t work for me. By the way, I have lost 35 lbs now.

  • Tala Daniela von Däniken

    Just read this article about interval fasting and found it very interesting. I have Poly Cystic Ovary Syndrome (PCOS) and therefore wonder if this would be a good eating plan for me or not? Thanks for your feedback

  • Tala Daniela von Däniken

    Would you recommend this for someone with PCOS? I am hesitant to try it incase it plays too much havoc with my insulin levels….

  • Pari

    Hi i have been doin if for 3 day like i eat my dinner at 10 pm like suppose sunday n then again i directly eat dinner at monday n then on tuesday is this fine to do cause i am feelin very good n i dont get hungry but i am confused how much calories should i intake.