The Beginner’s Guide to Intermittent Fasting

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

This rule has become so commonplace throughout the health and fitness community that it’s readily 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.

So, eat breakfast to lose weight and obtain optimal health.  Case closed…right?

Maybe you’re not getting the whole story. As skeptics, what we need to ask: what if there’s science and research that promotes SKIPPING BREAKFAST (the horror! blasphemy!) for optimum efficiency, 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 three months and might never go back to eating it.

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

Tony ain’t gonna be happy, but today we’re talking about intermittent fasting.

This is a topic that is very controversial, as it turns a LOT of conventional wisdom on its head. This is why this article is filled with more sources and citations than Jim Carrey’s glove compartment.

What is intermittent fasting?


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

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

By fasting and then feasting on purpose, intermittent fasting means eating your calories during a specific window of the day, and choosing not to eat food during the rest.

Now, there are a few different ways to take advantage of intermittent fasting:

  • Regularly eat during a specific time period.  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.  
  • Skip two meals one day, taking a full 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.

Now, you might be thinking: “okay, so by skipping a meal, I just eat less than normally overall, and thus I will lose weight, right?”  

Well, that’s partly true.  

Yes, by cutting out an entire meal, you are able to eat MORE food during your other meals and still consume a caloric deficit (which is an important for losing weight).  

However, as we already know that not all calories all created equal, the timing of meals can also influence how your body reacts.  

How does intermittent fasting work?


With intermittent fasting, 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 in its blood stream (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,” 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, rather than the glucose in your blood stream or glycogen in your muscles/liver.

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.  Essentially, the more sensitive your body is to insulin, the more likely you’ll be to use the food you consume efficiently, which can help lead to weight loss and muscle creation.

Along with that, your body is most sensitive to insulin following a period of fasting. 

Your glycogen (a starch stored in your muscles and liver that your body can burn as fuel when necessary) is depleted during sleep (fasting), and will be depleted even further during training, which can further increase insulin sensitivity. This means that a meal immediately following your workout will be stored most efficiently: mostly as glycogen for muscle stores, 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, enough glucose in the blood stream, and thus be more likely to get stored as fat.

Not only that, but growth hormone is increased during fasted states (both during sleep and after a period of fasting).  Combine this  increased growth hormone secretion, the decrease in insulin production (and thus increase in insulin sensitivity), 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.  For many different physiological reasons, fasting can help promote weight loss and muscle building when done properly.  

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

small plate

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 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.  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’re 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, I would argue most people find that eating six times a day is very prohibitive and requires a lot of effort.  Along with that, 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 really only works for people who struggle with portion control (#2).

If we want to think back to the 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, and his body adapted to still function optimally during the rest of the day.

A recent study (highlighted by the New York Times) has done a great job of challenging the “six-meals-a-day” technique for weight loss.  

Martin from LeanGains points out two important quotes from the study:

“…The premise underlying the present study was that increasing meal frequency would lead to better short-term appetite regulation and increased dietary compliance; furthermore, it was hypothesised that these predicted beneficial effects of increased meal frequency could have resulted from more favourable gut peptide profiles, potentially leading to greater weight loss. Under the conditions described in the present study, all three hypotheses were rejected.”

“…We had postulated that increasing meal frequency would enhance the compliance to the energy restricted diet thus leading to greater weight loss, an effect possibly mediated by increased fullness. The present results do not support this hypothesis.”

Remember, the type of food you eat matters. Meal frequency is not nearly as important as the quantity and quality of food consumed.  This study reached similar conclusions.

Why intermittent fasting?

IF fast plate

Because it works.  Although we know that not all calories are created equal, caloric restriction plays a central role in weight loss.  When you fast (either for 16 hours per day, or 24 hours every few days), you are also making it easier to restrict your caloric intake over the course of the week.  This will give your body a chance to lose weight as you’re simply just eating less calories than you were consuming before.

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 requires less time (and potentially 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.  This was already explained in the previous section with relevant sources, but intermittent fasting helps you create a double whammy for weight loss.

Plus, Wolverine does it.

What are the drawbacks with intermittent fasting?


In my own experimentation, I have found very few negative side effects with Intermittent fasting.  

The BIGGEST issue I’ve found, and 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.  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.

Yes, the initial transition from EATING ALL THE TIME, to intermittent fasting can be a bit of a jolt to the system. However, once you get through the transition, your body can quickly adapt and learn to function just as well only eating a few times a day:

This study explains that in participants after 48-hours of fasting, “cognitive performance, activity, sleep, and mood are not adversely affected in healthy humans by two days of calorie-deprivation.”

“So why do I feel grouchy when I’m not eating breakfast?” In this nerd’s humble opinion, a good portion of the grumpiness is a result of your eating habits. If you eat every three hours, your body will start 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.

It turns out, quite a bit of it is mental.

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 (thanks to a substance our bodies produce called Ghrelin).

Think about it in caveman terms again.  We certainly found ways to survive during periods of feast and famine, and that remains true today.  It actually takes our bodies about 84 hours of fasting 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 complex for people who have issues with blood sugar regulation, suffer from hypoglycemia, have diabetes, etc.  If you fit into this category, I highly recommend you check with your doctor or dietitian before adjusting your eating schedule.

I believe more research needs to be done for these particular cases and thus would recommend you do what works best for YOU.

Can I build muscle and gain weight while intermittent fasting?

muscle hypertrophy


In fact, I have been intermittent fasting for the past three months or so while building muscle, with minimal increase to my body fat percentage.  I still eat 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 massive Calorie Bomb 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.

This method has been borrowed from one of the best resources on intermittent fasting and muscle building on the internet: Lean Gains.

In a different method, my friend Nate Green packed on a crazy amount of muscle while fasting for a full 24 hours on Sundays.  

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. 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). I like Anthony Mychal’s technique of never being more than two weeks away.  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.

Does intermittent fasting have different effects on men and women?

boy girl

Yes, intermittent fasting does affect men and women differently.

This article over on Paleo For Women goes extensively into the negative effects of intermittent fasting for women.

This article on Mark’s Daily Apple does a fantastic job of breaking down the differences between men and women and how they are affected by intermittent fasting, ultimately explaining:

  • “One study, which I’ve cited before as evidence of a benefit to fasting, found that while IF improved insulin sensitivity in male subjects, female subjects saw no such improvement. In fact, the glucose tolerance of fasting women actually worsened. Ouch.
  • Another study examined the effect of alternate day fasting on blood lipids. Women’s HDL improved and their triglycerides remained stable; men’s HDL remained stable and their triglycerides decreased. Favorable, albeit sex-specific results.
  • Later, both obese men and women dropped body fat, body weight, blood pressure, total cholesterol, LDL cholesterol, and triglyercides on a fasting regimen. These people were obese, however, and perimenopausal women were excluded from the study, so the results may not apply to leaner people or women of reproductive age.”

Long story short: Yes, men and women will have different experiences with intermittent fasting; we’re all unique snowflakes (yep, even you), and your body will be affected by intermittent fasting differently than the person next to you.

My best advice?  Give it a shot, track your results, and see how things go!

Questions about intermittent fasting


“Won’t I get really hungry?”  

As explained above, this is generally 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.

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

“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.  And for my first workout or two, it was very weird to not eat a heavy carb meal 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.

As Mark’s Daily Apple states:

Fasted training can actually result in better metabolic adaptations (which mean better performance down the line), improved muscle protein synthesis, and a higher anabolic response to post-workout feeding (you’ll earn your meal and make more muscle out of it if you train on an empty stomach).

That being said, I’m currently experimenting with a pre-workout BCAA supplement to see the effect it has on muscle creation.  So far, so good, though I’m not sold on the necessity of the supplement yet.  I’ll keep you posted :)

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

Martin from LeanGains lays out a few different options for you, depending on your training schedule.  The best advice is to not freak out and overanalyze unless you are an elite athlete concerned with the absolute optimal performance at all time.

If you’re just a normal guy or gal looking to drop a few pounds and get stronger, do the best you can.

“Won’t fasting cause muscle loss?”  

Another big concern of mine, but it turns out…it 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!  This study shows that our bodies are quite adept at preserving muscle even when fasting, 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.    

“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.

As Martin from LeanGains so eloquently explains (as you can tell, he’s good at this stuff):

“The earliest evidence for lowered metabolic rate in response to fasting occurred after 60 hours (-8% in resting metabolic rate). Other studies show metabolic rate is not impacted until 72-96 hours have passed.

Seemingly paradoxical, metabolic rate is actually increased in short-term fasting. For some concrete numbers, studies have shown an increase of 3.6% – 10% after 36-48 hours (Mansell PI, et al, and Zauner C, et al).  Epinephrine and norepinephrine (adrenaline/noradrenaline) sharpens the mind and makes us want to move around. Desirable traits that encouraged us to seek for food, or for the hunter to kill his prey, increasing survival. At some point, after several days of no eating, this benefit would confer no benefit to survival and probably would have done more harm than good; instead, an adaptation that favored conservation of energy turned out to be advantageous.”

“This sounds crazy, I’m not gonna do it.”

That’s cool.  Are you losing body fat, building muscle, and getting a clean bill of health from your doctor?  If you can say yes to those things, AWESOME. Keep doing what you’re doing, because it’s working.   

However, if what you’re doing ISN’T working, or you’re not getting the results you were hoping for, why not give it a chance?  Hopefully the dozens of studies at least peak your curiosity.  Self-experimentation is the best way to determine WHAT methods work for you.

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 finely tuned 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.

Expect funny looks.  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 in our culture that NOT eating it sounds crazy.  You will get weird looks from those around you…embrace it.

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 (drinking green tea and listening to PM, which is exactly what I’m doing while writing this article!), and then comes my final hour of fasting: training.

I don’t have time to think about how hungry I am, because I keep my brain constantly occupied!

Zero-calorie beverages are okay.  As previously stated, 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!

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.

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. 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.

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.

Remember: One of the Rules of the Rebellion is to QUESTION EVERYTHING.  If this seems like something you’d like to try, give it a shot. If it sounds crazy to you, ask yourself why you think it sounds crazy, and do your own research and experimentation before condoning/condemning it.

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: We’re fans of Intermittent Fasting, which is why its part of the Nerd Fitness Academy, our online training course that is helping over 4000 superheroes-in-training get fit, healthy, and happy.  Come on and join us!

PPS: Added an important caveat:  If you are somebody who has blood sugar regulation issues (diabetes, hypoglycemia, etc.), I strongly recommend you discuss with your doctor or medical professional before making changes to your diet.  Remember, question everything!


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

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  • Blazer

    that’s just sad :-( okay, so then I’m actually just doing 12 hr fasting in that case…still pretty good, but I’ll change that by not having BPC on scheduled fast days. I’ll test it out tomorrow morning (my scheduled fast day).


    I too started doing this before I realized there were so many others doing it and so many variations! my question though is water / coffee consumption, is there benefits for consuming or not consuming either during fasting? it kind of goes against the grain not consuming H2O for 24hrs, buut thats what i have been doing every other day. my schedule is 24hr fast (0 intake of food and liquid) 24hr normal intake, continuously, what are your thoughts on effectiveness?

  • fiuza78

    I don’t know how BPC is assembled, but if you don’t add the butter and coconut oil, it’s ok. Just use the beans. You wont break your fast if you drink non-calorie drinks like coffee and tea (no added sugar). I like to drink either one to get started!

  • fiuza78

    I don’t know about not drinking water. You can get dehydrated fairly easily. You can do pretty well and even do intense exercise on a fasting period, but to not drink water would ruin my day. I haven’t read any benefits about it.

  • Noah

    I was a bit confused…is this meant to be done every day or can I do it 2x a week. For example, Tues/Thurs on my lighter days/cardio days. and then eat the normal 6 meals a day on my three lifting days when I want to have a bit more calories and fats.

  • Pingback: Becoming Antifragile: How to Prepare Yourself for Chaos | Nerd Fitness

  • fiuza78

    Hello Noah,
    You can do a 16h fast every day, or a 24h fasting once a week.
    I prefer doing a 16h fast everyday. My eating window is from 1pm to 9pm.

    Prior to a 24 hour fasting I suggest you do a BIG meal. And choose your most inactive day of the week to do it!

    When you get used to a daily 16h fast you will find much easier to try the 24h once in a while!

  • Allison

    So how many calories should I be consuming daily when fasting every day from 20:00-12:00?


  • SDK

    Do you have something against fucking naturopaths? I think some of them are cute, myself.

  • fiuza78

    Hello Allison,
    You should aim for the same amount of calories. For example, if your diet is 2,500 calories, you should try to fit that amount in your 12:00 – 20:00 eating window.

    Intermittent fasting is not about calories shortage, but about optimizing you body for burning fat!

  • fiuza78

    Hello Allison,
    My comment wasnt attached as reply, read my new comment.

  • DBLTAP22

    2 years ago I did the whole 5meals a day at around 250 calories per meal and rode my bike for 1.5-2 hours few times a week. shed weight and never ever felt weak. switched it up in the winter with lifting and gained some good size and strenght. put on some weight, but that was mostly muscle mass, kind of a bulking phase. when i started the 5 meals i was 240 lbs dropped down to 195lbs. gained some back to 211 lbs. Life, less working out, and more drinking, etc…

    I’ve been IF with a 6 hr window for a 2 months now. no real results until this month. the first month i wasn’t really watching the actual calorie intake. it wasn’t huge, and wasn’t too low. this last month i have been dropping down to 500 to 800 calories. walking 6 miles a day. My HRM and Phone gps show an avg of 800 calories burned. I feel fantastic. I’ve dropped 9lbs this month. Over 2LBS per week. Im 40 y/o 6′ male 202 lbs. no weakness or mental issues.

    My issue/question is, conventional wisdom says “no less than 1200 calories a day. Now that i am accustomed to LCD and cannot eat anymore in my 6 hr window. I feel like crap when I try to kick it up to the RDA. lethargic and bloated. I never had any metabolism slowdown with my 5 meal a day for a year. lost weight, felt great, strong, endurance, etc… I did get sick of the planning and watching the clock until my next feeding though.

    I get that every person is different. One eating style may not work for another. But i can’t lump myself in with the RDA crowd. I get my loses may slow down. my body will be in better shape and become more efficent. and that I will have to work harder to keep dropping LBS, I will approach that when it comes. but I had a year of total success dropping 45lbs. was on my way to 190 if i hadn’t upped the alcohol and been on the road so much.

  • JD

    I’ve been doing this but having protein shakes now and then (about 120 calories according to the tub) to ward off hunger. Keeps me sane while working. So far weight loss is pretty good.

  • Mark

    Back in college I only ate from 12 pm to 8 pm unintentionally. I only have candies to suppress my appetite. After two months I lost 8 kg. Our clinical instructor though I was sick or something. I started to have a beautiful perspective because I was fit. I got a girlfriend. I didnt know they have a name for this diet now. Intermittent fasting.

  • Jacqueline Carrilho

    wow i am so happy i found this article!!!! i see the last comment was left over a year ago so hoping someone will reply! I started this intermittent fasting 4 days ago and i wish I had found this method of eating ages ago! I met a girl over the past weekend, she had a beautiful figure and I noticed when a plate of snacks were brought out to the table she never touched a thing! i asked her why she wasn’t eating and she said she NEVER snacks and only eats 2 meals a day, I thought wow I think i could do that! I started researching and found leangain and have been following that way of intermittent fasting. I was on Paleo last month and it was great but i had sugar cravings and often ended up binging, and i think it all came down to pressure of not being able to eat so many things even though i know its such a healthy lifestyle to follow. So I am 4 days in and doing great! no craving, not starving and no sugar cravings! honestly i am shocked at how well my body is responding to this type of lifestyle. first time in my life i can see myself doing this forever! i am not over weight but do want to loose a couple of kilos and tone up (started the jillian michaels 30 day shred -amazing) I just wanted to ask 1 question! should i be avoiding carbs in the evening if i want to loose body fat? i am not eating any processed food and i am eating protien and veg and fruit but i do worry if i eat a wholewheat sandwich for lunch and then have a portion of rice in the evening i might not loose body fat? should i just stick to one carb a meal instead of having carbs at both meals? please help me with this question.

    i would appreciate it greatly! thanks for this article it has made me even more motivated and confident in my new lifestyle :-)

  • fiuza78

    Hello Jacqueline,

    It’s ok to eat carbs at night as long as you dont exceed 100g of carbs per day. For optimum weight loss aim for 50g – 70g grams of carbs per day.

    For example, 50g of wholebread (2 medium size slices) has around 35g of carbs.
    100g of brocolis has around 5g of carbs.

    One banana has 25g of carbs.

    Pick your fruits and veggies wisely!

    By the way, are you brazilian?

  • Mc

    Hi! I’m a female weighing 160, height is 5’4 and I’ve been working out for a solid month and the scale and mesurement haven’t buged. I don’t know what I’m doing wrong and came across this website to see if I can give it a shot. I downloaded my fitness pal and I’ve been sticking to my appropriate calorie consumption it’s suggesting I stick to in order to loose 10-15 lbs but i do consume below sometimes . I do t25 workout and bike for 40 min 5-6 days a week. My daily food consumption consist of :before I workout, which Iread it wasn’t good to do on here, sometimes a bowl of Cheerios or whole grain cereal or a hard boil egg with whole grain bread or one slice of whole grain bread with PB and tea. after my workout I sometimes drink a meal replacement shake with milk it adds to 200 calories or sometimes a hard boiled egg sandwich on whole grain toast and tea, or corn meal dumpling steamed with eggs. I snack on nuts or yogurt or fruit salad, and for dinner anything that has lean protein with a brown rice or cassava a none starch bread/non sweet cookie like, I Like the crunch. T 25 workout has my legs feeling leaner which I love but not sure what I’m doing wrong here, is it muscle I’m building or my fat is not moving along anywhere. I’ve never had a problem loosinng weight but before I’ve done drastic fasting and pills to loose weight and I’m trying to do it the ol hard way this time to continue a long term life style. Hope somebody could reply! I’ll give the fasting a try in the mean time.

  • Jacqueline Carrilho

    thanks so much for replying! and thanks for the help! appreciate it.

    I am Portuguese :-)

  • nobody

    Hi! I’m in the US (yes, a “d**n yank”….but a friendly one) and am wondering how many calories I should intake if I skip breakfast and only eat from 12pm to 6pm. I’m only 4 foot 11 but weigh 220 lbs. and am prediabetic. Thanx! :)

  • fiuza78

    Hello nobody!

    You should not worry much about your calorie intake to lose weight and fix your blood glucose. You though MUST count your carb intake.

    It’s possible to reverse your Prediabetes. But you should lower your carb intake to 50g – 100g daily at most!

    Anyway, you should see a doctor and get some blood tests done for a better approach to your problem!

  • Faylinameir

    I’m an american also but I says Break-fast. Some people say it like brek-fast but ever since I realized it was the literal breaking of the fast (you’d be SHOCKED at how many people don’t realize that’s why it’s called breakfast fyi) I just started saying it like it’s spelled.

  • Blazer

    fiuza78 I wanted to let you know that I’ve been successfully fasting for 24 hours for 4 days now and doing well. My pants are actually fitting me loose these days. I drink a lot of water throughout the day. So yeah…24 hour fast is a lot easier than I thought. The first day of my 24 hour fast (without taking the bullet proof coffee in the morning) there was only 2 instances that I thought about hunger…NOT felt it…but just thought of it, and had a buzzing headache, but since then everything has been smooth sailing for me.

    So I do 2 or 3 days of 24 hour fast in the week and the rest I try to do at least 16 – 18 hrs as much as possible.

  • Jack Menendez

    I like this diet because it is so easy to know when and what to eat. I am using a form of this diet called the Babybel diet named after the little cheeses. It is very easy to stay on. I started at 205 lb and after 8 weeks i am at 183 lb. I want to be 165 lb. All you do is have normal breakfast and lunch, nothing after noon. Then for dinner have one Babybel or .75 oz of any cheese only; nothing else!. The fat in the cheese satisfies your hunger. The small meal of the cheese shrinks your stomach. This diet helps older people sleep better. I workout in the evening or before breakfast.

    There is one catch, this diet is in some form permanent or you will gain the weight back.

  • Jenni J

    I never used to eat breakfast when I was a teenager and early 20s and I was thinner then. I also wasn’t hungry. It makes sense. I feel like as I’ve gotten older all I think about it FOOD, when can I eat, what can I eat, how much do inhale left to eat, blah blah blah. I think it’s definitely worth a shot to try.

  • Andrew

    Love this! My method is this – about once every week or two weeks I skip breakfast and lunch one day and just eat dinner. I usually have a cup of black coffee in the morning and a cup of peppermint tea at lunch time. The first time I did it, I only had water until dinner. I had a really bad headache most of the day due to the caffeine withdrawal but I’m tapering myself off of the caffeine so I hope that will get better. I originally decided to do this because at age 26 I was staring down the barrel of being put on blood pressure medication. A paleo lifestyle, exercise, and intermittent fasting definitely helped! (And I am NOT on meds! Approximately a year from starting to try to eat “as paleo as possible” and my blood pressure has dropped to within normal range.)

  • Ronda

    GREAT article! Very entertaining too. I like your writing style. I started this 3 days ago. I am not hungry in the mornings normally so it’s perfect. I am however typically STARVING at 3 pm, but after my 11 AM workout (which I do have MORE energy for!) and eat my first big meal, I’m full until 6 PM dinner. This works great for me although I am tired in the mornings working behind my laptop for hours. I just read this article to read from another source to be sure I was doing it right. Thanks so much for all the info!

  • curioustotrythisout:)

    In your eating window how many calories should you take in? Should it be all the calories for the day? Or does it matter how many calories you take in?

  • G

    Sounds great been doing this for four days now let’s see how it goes!

  • Internet Geeks

    I have started fasting from this week. I had already seen some good result. Combining fasting with low carb diet working well for me for now. I hope to get back to my optimal weight in next 5-6 months.

    Thanks for all these information and useful links that you provided in this post.

  • Allie

    This is really interesting to me! I stumbled onto some IF information on tumblr earlier and while I had heard about it before, I’d never paid much attention. I’m actively trying to lose weight and my schedule is inconvenient when it comes to eating, so I’ve apparently been accidentally fasting. This post was incredibly informative to me, so thank you! :)

  • Kick Abs

    Very interesting read! Thanks for this great article on something I didn’t realize… which is that intermittent fasting was a system or “thing-to-do”. Personally, I will NEVER choose to skip breakfast. That’s just me. But I can and often do skip dinner. About 3 times a week I have a large breaky then delay eating a full sized lunch until around 2 or 3 pm and have what I call “Lupper”. For me, this helps keep my energy up during the day and I never feel hungry. I also eat a paleo-ish type diet. This works really well for me.

  • Dope In Charge

    Just a silly question about burning fat instead of carbs… It takes more than a few days for your body to become “fat adapted” and to do so, you need to REALLY back off from the carbs. To starve the body of carbs (25 or less a day) and burn fat as an energy source (and your body will do this, Eskimos live pretty much carb free and survive quite well), it will take several days. So how can you go back and forth between fasting & feasting and burn fat so easily?

  • Aurora Dowell

    I have been doing a 6 hour window for 2 weeks now, with struggles, I have found that when I stay the course I can drop a pound or two after just a few days. I like intermittent fasting because its a cheap easy, one rule way to try to drop weight. My wii tells me I am obese, so maybe that is why it works. I will look for more research regarding women and fasting like this as the information about its negative effect on blood glucose was unclear.

  • Premed

    While I agree with the majority of the article and am a proponent for fasting, I find the statement, “glucose in the bloodstream will be stored as fat” to be highly inaccurate. You say insulin brings glucose into the cells: CORRECT. However, glucose cannot be stored as fat if it is in the bloodstream due to low insulin sensitivity. Fat cells are intercellular, anything extra cellular will be passed by the body and not absorbed. So I do not understand your statement of excess glucose in the bloodstream of the body will be stored as fat because it is biologically impossible.

  • Dharmagirl223

    I was just introduced to this idea by a neighbor. In the past I fasted once a week for several months. I lost 25 pounds (about 5lbs a month). The rest of the week I ate what I wanted. Right now I am trying eating only one meal a day in the evening, in conjunction with Circadian rhythms. It makes sense and feels good. I also noted how nice it will be to do fewer dishes, spend less time in the kitchen, and save money on food. I hope to keep up with this and report back good results. Not eating during the day gives me more energy all day long and I am more productive. So nice not to have to break up my routine when I am in the middle of accomplishing things to stop and eat.

    Also, I am prediabetic, or insulin resistant. After the second day of eating one meal a day in the evening, my fasting blood sugar went from 113 to 98. A whopping 15 points that I couldn’t achieve before no matter what I tried.

    P.s., I have always hated the notion of eating 6x a day. What a chore!

  • Dupont

    I’m french and about a year ago I started what I call a diet of my own without knowing it was intermittent fasting ! I explain myself :) I don’t really like sugar so it’s almost natural for me not to have breakfast. I dared it and now I’m slim, eating what I like (club sandwiches, pizzas…) in small/medium portion of course.

  • Tiffany

    I really enjoyed the authors tone! Starting IF tomorrow!!

  • Nol

    Really interesting, and thank you for mentioning the differences that can occur between men and women! Representation of women of reproductive age is a general problem in clinical tests (apparently too expensive and time consuming to factor in women’s hormonal cycles…), most medicine we use have been tested on men only.

  • fiuza78

    Glucose can cause microvascular damage on your nerves, kidney and eyes. If your glucose level on your bloodstream is too high and your insulin cant take it out due to insulin resistence, the liver will take action and convert the glucose into triglycerides. Also glucose has free pass into fat cells (no insulin needed).

    Plus, it sounds a bit weird to never get fat by eating sugar only.

  • fit-grammar-nerd

    Not sure if you’re likely to see this or care but “peak your curiosity” should be “pique your curiosity” :)

  • dany

    i have always eaten breakfast and always struggled with over eating but have always been very active i was never very over weight just maybe 5 kg i eat healty no junk and mostly low carb ..i have been skipping breakfast now for a few days and feel great for it im less hungry and feel more in control its the easiest meal to leave out for me energy is better for it not less might not be for everyone and i might not tell anyone because i know what the reaction will be .. but if at first an idea doesnt sound absurd there is no hope for it

  • Virgil Dunmeyer

    I’ve found this article right on point! I’ve been doing some research on IF for some time now and have just completed my first week. Of course, there are tons of associates around me who’ve questioned EVERY thing regarding IF and have gone so far as to keep track of when and what I eat. Truthfully, I’ve never felt better; I’m more mentally alert, focused, and my energy levels have gone through the roof. I feel like a great burden’s been lifted; I no longer have to pack food and plan out my meals throughout the day. I’ve almost always worked out in a fasted state, and I’ve done this for years. Something inside told me that it just made sense, so I’ve done it. I don’t know how much weight I’ve lost (I won’t have access to a scale for another two weeks), but I can see the difference and feel my clothes fitting much looser.

  • Sam Fahringer

    Stephen is it possible that when working out during the fast period your body will draw energy from protein instead of the fat cells? If that’s the case, couldn’t it possibly lead to less strength/muscle gains?

  • ookie19

    Funny, I have been doing this for years but had no idea it had a name. I was a cook for 20 years. I would eat my dinner early in the evening and then not eat again until I had lunch ready for my clients at noon! Of course I would eat lunch and snacks throughout my cooking day, have dinner and go to bed. Start all over again the next day. I retired but continue my “no breakfast” routine. Now it’s fashionable! Incidentally, I have never had a weight problem and most people guess my age minus 15 years. I think I like this intermittent fasting!!

  • Greg – Kinobody

    I’d much rather see you fast daily. It will work better with appetite regulation to get on a set up. And daily fasting works amazing at improving nutrient partitioning (muscle gain and fat loss).

  • Greg – Kinobody

    HAHAHA! Thanks :)

  • devans00

    I’m taking the intermittent fasting, alternate day method, plunge tomorrow. Thanks for the helpful tips.

  • dawnaj22

    I want to buy your ebook and really try the IF, however, I AM NOT a counter and I know that I will not count my calories and my macros etc..I just lifestyle wont permit…so is IF worth doing if I am not going to do that? I still eat pretty reasonable in my 8 hour window…but if I am not going to see results with out counting my macros I dont want to try this.