A growing number of experts claim short fasts can accelerate fat loss and make you healthier. So we spent 6 months testing the most popular Intermittent Fasting (IF) protocols ourselves.
Find out what IF is, whether you should do it, and if so — how.
For years, Dr. John Berardi, Chief Science Officer of Precision Nutrition, has advocated frequent meals, spaced 3-4 hours apart, consisting of nutrient-dense, healthy food. That strategy — when combined with a smart exercise program and world-class coaching — has helped thousands of our clients drop over 120,000 pounds of fat in the last ten years.
Proponents of IF, on the other hand, eschew the idea of eating so frequently. Many claim to have achieved quicker fat loss and better health by deliberately skipping meals and sometimes going entire days without eating.
The IF research is still in its infancy — indeed, it may be 5-10 years before it reaches critical mass and becomes a mainstream nutritional idea — but in certain quarters, the benefits of intermittent fasting have reached almost mythical proportions.
With research lagging behind at a snail’s pace, but enough anecdotal evidence to go off of, we decided to do what we do here at Precision Nutrition: test it ourselves.
Here’s what Dr. Berardi found, in his own words.
Why Experiment With Intermittent Fasting?
I’m a professional dieter. In other words, I’ve done nearly every diet or nutritional protocol that’s around to test its efficacy.
Intermittent fasting has a very small, yet strong, following and enough research to pique my curiosity. I wanted to test it myself to see what kinds of physiological and psychological changes would come from it.
Also, as a competitive, masters-level track athlete and life-long fitness enthusiast, I wanted to test a new way to drop fat and get extremely lean, while staying strong and powerful.
What Did You Test?What Happened?What Are The Big “Takeaways”?So Intermittent Fasting Is Good, But Not Necessary?
Since there isn’t one definitive intermittent fasting protocol, I decided to test six different methods over the course of six months.
I kept meticulous notes on everything from scale weight, body-fat percentage, and blood/hormonal markers, to lifestyle markers like energy levels, cognitive thought, and pain-in-the-ass factors.
Over the course of six months, I dropped twenty pounds of weight, from 190 pounds to 170 pounds. I also reduced my body fat from 10% to 4% while maintaining most of my lean muscle mass. Finally, I found two intermittent fasting strategies that I could follow indefinitely with no problem.
Simply, I accomplished the goals I set for myself in a way that was easier and less time-consuming than “traditional” dieting.
I think there are four main takeaways that readers of this book should come away with.
Trial fasting is a great way to practice managing hunger. This is an essential skill for anyone who wants to get in shape and stay healthy and fit.
More regular fasting isn't objectively better for losing body fat. While my IF experiments worked quite well, the intermittent fasting approach (bigger meals, less frequently) didn't produce better fat loss than a more conventional diet approach (smaller meals, more frequently) might have.
More regular fasting did make it easier to maintain a lower body fat percentage. Intermittent fasting isn't easy. However, I did find that using this approach made it easier for me to maintain a low body weight and a very low body fat percentage vs. more conventional diets.
Intermittent fasting can work but it's not for everyone, nor does it need to be. In the end, IF is just one approach, among many effective ones, for improving health, performance, and body composition.
Exactly.
Intermittent fasting can be helpful for in-shape people who want to really get lean without following conventional bodybuilding diets, or for anyone who needs to learn the difference between body hunger and mental hunger. (And for the latter, I only recommend the Trial Fast.)
It’s a helpful tool and one I’ll continue to use periodically. But it’s not the end-all, be-all of nutrition or fitness. People have been getting in awesome shape — and staying in awesome shape — for decades without the use of intermittent fasting.
How Are IF and "Grazing" Similar?
Successful nutrition plans, whether they use smaller, more frequent meals or larger, less frequent meals all share a few commonalities. These include:
Controlling calories. When calories are controlled, progress is made. Whether you control them by eating frequent small meals or infrequent larger meals is up to you.
Focusing on food quality. Fresh, unprocessed, nutrient-dense food is a must, regardless of which eating style you adopt.
Regular exercise. Exercise is a critical part of the equation.
Once those three have been taken care of, it’s a matter of personal preference and lifestyle considerations.
I'd Like To Learn More. What's Next?
Have 10 minutes? Read Appendix A. It's a cheat sheet that shows you exactly how to do intermittent fasting, including specifics on our three favorite protocols.
Have 30 minutes? Read about the individual fasts in Chapters 4, 5 and 6. Then read the cheat sheet in Appendix A. Then check out Appendix B for some tips and tricks we learned along the way.
Have an hour or two? Read the entire Experiments with Intermittent Fasting book. We spent a lot of time researching, conducting the experiments, and writing. We’d love to share it with you and hear your thoughts.
I've noticed a couple curious things lately in regard to eating and exercise. First, I've noticed that if I ocassionally skip dinner, or just have some carbs like potatoes but no meat for dinner, that I actually feel better upon waking the next morning. Of course, I'm not doing this every day, but if I do this once or twice a week, then I am virtually guaranteed to feel better the next morning. This points to how occassionally restricting calories in the evening, or perhaps restricting protein in the evening seems to yield benefits.
Today, I noticed how this carried over into exercise. I have been exercising fasted in the morning, going for an intermittent run on the nearby trail. Last night, I just had some potatoes instead of dinner, and this morning I ran before eating anything. This combination seemed to really prime my body for running. I don't know if it put me in "fat-burning" mode or something, but I was just really cruising on the trails today.
It's amazing how good you can run on an empty fuel tank. I wish someone would have told me about this 15 years ago. I remember reading Runner's World for a few years straight back in my twenties. Never once did I see an article that recommended running while fasted. Guess it wasn't the expert publication it was supposed to be!
"A fat-burning beast is able to effectively oxidize dietary fat for energy. If you can handle missing meals and are able to go hours without getting ravenous and cranky (or craving carbs), you’re likely fat-adapted.If you can handle exercising without having to carb-load, you’re probably fat-adapted. If you can workout effectively in a fasted state, you’re definitely fat-adapted."
When describing someone that has successfully made the transition to the Primal way of eating I often refer to them as “fat-adapted” or as “fat-burning beasts”. But what exactly does it mean to be “fat-adapted”? How can you tell if you’re fat-adapted or still a “sugar-burner”? I get these and related questions fairly often, so I thought I’d take the time today to attempt to provide some definitions and bring some clarification to all of this. I’ll try to keep today’s post short and sweet, and not too complicated. Hopefully, med students and well-meaning but inquisitive lay family members alike will be able to take something from it.
As I’ve mentioned before, fat-adaptation is the normal, preferred metabolic state of the human animal. It’s nothing special; it’s just how we’re meant to be. That’s actually why we have all this fat on our bodies – turns out it’s a pretty reliable source of energy! To understand what it means to be normal, it’s useful examine what it means to be abnormal. And by that I mean, to understand what being a sugar-dependent person feels like.
A sugar-burner can’t effectively access stored fat for energy.
What that means is an inability for skeletal muscle to oxidize fat. Ha, not so bad, right? I mean, you could always just burn glucose for energy. Yeah, as long as you’re walking around with an IV-glucose drip hooked up to your veins. What happens when a sugar-burner goes two, three, four hours without food, or – dare I say it – skips a whole entire meal (without that mythical IV sugar drip)? They get ravenously hungry. Heck, a sugar-burner’s adipose tissue even releases a bunch of fatty acids 4-6 hours after eating and during fasting, because as far as it’s concerned, your muscles should be able to oxidize them (PDF). After all, we evolved to rely on beta oxidation of fat for the bulk of our energy needs. But they can’t, so they don’t, and once the blood sugar is all used up (which happens really quickly), hunger sets in, and the hand reaches for yet another bag of chips.
A sugar-burner can’t even effectively access dietary fat for energy.
As a result, more dietary fat is stored than burned. Unfortunately for them, they’re likely to end up gaining lots of body fat. As we know, a low ratio of fat to carbohydrate oxidation is a strong predictor of future weight gain.
A sugar-burner depends on a perpetually-fleeting source of energy.
Glucose is nice to burn when you need it, but you can’t really store very much of it on your person (unless you count snacks in pockets, or chipmunkesque cheek-stuffing). Even a 160 pound person who’s visibly lean at 12% body fat still has 19.2 pounds of animal fat on hand for oxidation, while our ability to store glucose as muscle and liver glycogen are limited to about 500 grams (depending on the size of the liver and amount of muscle you’re sporting). You require an exogenous source, and, if you’re unable to effectively beta oxidize fat (as sugar-burners often are), you’d better have some candy on hand.
A sugar-burner will burn through glycogen fairly quickly during exercise.
Depending on the nature of the physical activity, glycogen burning could be perfectly desirable and expected, but it’s precious, valuable stuff. If you’re able to power your efforts with fat for as long as possible, that gives you more glycogen – more rocket fuel for later, intenser efforts (like climbing a hill or grabbing that fourth quarter offensive rebound or running from a predator). Sugar-burners waste their glycogen on efforts that fat should be able to power.
Being fat-adapted, then, looks and feels a little bit like the opposite of all that:
A fat-burning beast can effectively burn stored fat for energy throughout the day.
If you can handle missing meals and are able to go hours without getting ravenous and cranky (or craving carbs), you’re likely fat-adapted.
A fat-burning beast is able to effectively oxidize dietary fat for energy.
If you’re adapted, your post-prandial fat oxidation will be increased, and less dietary fat will be stored in adipose tissue.
A fat-burning beast has plenty of accessible energy on hand, even if he or she is lean.
A fat-burning beast can rely more on fat for energy during exercise, sparing glycogen for when he or she really needs it. As I’ve discussed before, being able to mobilize and oxidize stored fat during exercise can reduce an athlete’s reliance on glycogen. This is the classic “train low, race high” phenomenon, and it can improve performance, save the glycogen for the truly intense segments of a session, and burn more body fat.
If you can handle exercising without having to carb-load, you’re probably fat-adapted. If you can workout effectively in a fasted state, you’re definitely fat-adapted.
Furthermore, a fat-burning beast will be able to burn glucose when necessary and/or available, whereas the opposite cannot be said for a sugar-burner. Ultimately, fat-adaption means metabolic flexibility. It means that a fat-burning beast will be able to handle some carbs along with some fat. A fat-burning beast will be able to empty glycogen stores through intense exercise, refill those stores, burn whatever dietary fat isn’t stored, and then easily access and oxidize the fat that is stored when it’s needed. It’s not that the fat-burning beast can’t burn glucose – because glucose is toxic in the blood, we’ll always preferentially burn it, store it, or otherwise “handle” it – it’s that he doesn’t depend on it. I’d even suggest that true fat-adaptation will allow someone to eat a higher carb meal or day without derailing the train.
Once the fat-burning machinery has been established and programmed, you should be able to effortlessly switch between fuel sources as needed.
There’s really no “fat-adaptation home test kit.” I suppose you could test your respiratory quotient, which is the ratio of carbon dioxide you produce to oxygen you consume. An RQ of 1+ indicates full glucose-burning; an RQ of 0.7 indicates full fat-burning. Somewhere around 0.8 would probably mean you’re fairly well fat-adapted, while something closer to 1 probably means you’re closer to a sugar-burner. The obese have higher RQs. Diabetics have higher RQs. Nighttime eaters have higher RQs (and lower lipid oxidation). What do these groups all have in common? Lower satiety, insistent hunger, impaired beta-oxidation of fat, increased carb cravings and intake – all hallmarks of the sugar-burner.
It’d be great if you could monitor the efficiency of your mitochondria, including the waste products produced by their ATP manufacturing, perhaps with a really, really powerful microscope, but you’d have to know what you were looking for. And besides, although I like to think our “cellular power plants” resemble the power plant from the Simpsons, I’m pretty sure I’d be disappointed by reality.
No, there’s no test to take, no simple thing to measure, no one number to track, no lab to order from your doctor. To find out if you’re fat-adapted, the most effective way is to ask yourself a few basic questions:
Can you go three hours without eating? Is skipping a meal an exercise in futility and misery?
Do you enjoy steady, even energy throughout the day? Are midday naps pleasurable indulgences, rather than necessary staples?
Yes? Then you’re probably fat-adapted. Welcome to normal human metabolism!
A quick note about ketosis: Fat-adaption does not necessarily mean ketosis. Ketosis is ketosis. Fat-adaption describes the ability to burn both fat directly via beta-oxidation and glucose via glycolysis, while ketosis describes the use of fat-derived ketone bodies by tissues (like parts of the brain) that normally use glucose. A ketogenic diet “tells” your body that no or very little glucose is available in the environment. The result? “Impaired” glucose tolerance and “physiological” insulin resistance, which sound like negatives but are actually necessary to spare what little glucose exists for use in the brain. On the other hand, a well-constructed, lower-carb (but not full-blown ketogenic) Primal way of eating that leads to weight loss generally improves insulin sensitivity.
That’s it for today, folks. Send along any questions or comments that you have. I’d love to hear from you guys.
Overall my thoughts,... it’s a fun program to follow that allows you to eat some of the foods you love on a more regular basis.
Going forward I will probably be practicing a hybrid of intermittent fasting mixed with a little backloading.
GUIDE: Carb back loading
Sitting here tonight writing this article eating ice cream is a little out of the normal routine for a fitness professional and competitor like myself. As we all know eating things like ice cream and pizza are reserved for only extreme cheat days, or at least I thought that was the case. However, over the past few months I have amerced myself deep into the world of Carb Back loading. Eating things like ice cream, cookies, and various “cheat foods” post workout all while keeping my body fat in single digits during that span. Now many of you are wondering what the heck is carb back loading?
What is Carb Back Loading?
Well to get started quickly Carb back loading in a nutshell is when you back load your carbs so you are eating no carbohydrates before you workout, only proteins and fats throughout the day and saving all your carb consumption for post workout.
Yes, you are reading that correctly you only eat carbs after you strength train and ZERO carbs before.
I am not talking just eating brown rice and oatmeal after training, I am talking ice cream, cookies, milk shakes, and pizza in fact according to the research those simple sugars work best with back loading. Now before you do condemn me to the mad house, this theory was made popular by a guy named John Kiefer a Physicist who became a nutritionist, so there is some science and education to this method.
Now I come from the world of 'IF' intermittent fasting, (fasting for a minimum of 16 hours and eating for the remaining 8 hours of the day) so many of the principals in carb back loading came easy to me, as there is a fasting concept inside the back loading.
Before I get into that, let’s start from the main idea, when you sleep you are fasting essentially and when you wake up your body is a fat burning monster. Research has shown that cortisol which we know is a stress hormone rises while we sleep, and for most people on a regular schedule it peaks in the early morning around 7am.
The idea with carb back loading is to wake up and eat nothing, that’s right the whole breakfast is the most important meal of the day idea is gone. In fact if you guys end up researching carb back loading on your own you will hear John Keifer say “breakfast sucks”. The reasoning for this is you want your cortisol level to drop, which they do naturally later in the day a few hours after waking up. To break it down you wake up, drink nothing but coffee or water and let your body just burn fat like crazy until you eat your 1st meal.
So, assuming you train later in the day after work let’s say 6pm, what does one eat during the day when they are carb back loading? It’s simple really, just proteins and fats and ZERO carbs during the day before you workout. I know most magazines and professionals will disagree with this as they suggest eating carbs pre-workout is essential and needed for energy.
Honestly I use to think the same thing years ago, that I needed carbs before I workout or I will have no energy and be sluggish. The reality is you don’t need them pre-workout you can train all out hardcore on proteins and fats. The idea behind it is just like the short morning fast, without eating carbs pre-workout you can burn even more fat will you train during the session. I have found I feel more energized, motivated, and train like a maniac on no carbs pre-workout; you will be surprised when you give it a try for the 1st time how well you perform.
The Plan
Here is the basics on how to get started if you think this is for you.
To prime your body for this new eating style and lifestyle honestly you must go extremely low carbs for 10 days – Kiefer prescribes 30g or less each day. That’s right 10 days of 30g carbs or less, and trust me on this, it’s the hardest part of this whole program. We are only talking 10 days, which anyone can struggle through if they are serious about training and making changes.
Protein intake is pretty standard 1g per pound – so if you are 200lbs eat 200g of protein per day. You can also eat as much fat as you like; now keep in mind proper judgment on this. Things like cheese, avocados, bacon, whole eggs, coconut oil and the list goes on and on. The restrictions on this program are limited, it’s based heavily on how you look in the mirror and feel from day to day.
On the 10th day of your low carb intake after you train that evening you can, as they say “carb up”. Your body will be ready to take in some serious carbs, and this is where the fun starts.
Consume around 1g of carbs per pound of bodyweight so if you weight 200lbs eat 200g of carbs or a little more if your body can handle it. The main thing to remember here is these are high-glycemic foods, ice cream, cup cakes, cookies, fries, pizza and so on.
You will probably go to sleep full and bloated feeling happy and fat, upon waking you will probably find yourself looking lean and ripped.
Now you are in the world of carb back loading, from here on out, on all days you strength train (lift heavy weight) you can carb backload. On days you don’t strength train and just do cardio or have rest days eat as you would during the 1st 10 days with 30g of carbs of less just eating proteins and fats.
That in a nutshell is the basics of carb back loading and how it’s done.
A few other tips and my thoughts before you get started -
Protein intake is 1g per lb per bodyweight.
Fat intake is at your own discretion, just be cognizant of the number.
Carbs on your off days 30g per day or less.
Carbs on backloading days range from 1 - 2g per lb of your bodyweight so for a 200lb man that would be 200g-400g carbs per back load. If your looking to lose more body fat keep the carbs closer to the 1g, if you are looking to gain a little size keep it closer to the 2g per lb.
If you train in the morning there are modifications in the book Kiefer put out and he breaks down exactly how to do it.
Keep your protein and carb numbers in mind while you eat, but more importantly just check the mirror to see how you feel and look each day. If you are looking lean and ripped after time you are on the right path, if you feel bloated and look doughy odds are you might be overdoing the back loading so cut back on the carbs for a few days.
Conclusion
Overall my thoughts,... it’s a fun program to follow that allows you to eat some of the foods you love on a more regular basis. It also allows you to eat with friends and family enjoying pizza and ice cream from time to time. It’s not for everybody, but if you really struggle with your cheat meals this just might be the thing that gets you to the next level. It’s been a fun few months backloading as I love pizza and ice cream just as much as most people. Going forward I will probably be practicing a hybrid of intermittent fasting mixed with a little backloading.
From a health stand point there will be arguments on eating ice cream and pizza every week, from a personal standpoint my blood work has been as clean as ever even while integrating these foods into my life over the past few months. Again do a little research on your own and become educated on what best fits your health and training needs before moving forward. Best of luck and happy eating!
Resources: CBL 1.0 – for more info carbbackloading.com
Author - Jeremy Scott is the creator of www.jeremyscottfitness.com , PROLAB Sponsored Athlete, Nationally Published Author, and currently lives in and trains in Scottsdale, Arizona.
In 2008 I began experimenting with Intermittent Fasting (IF). Intermittent Fasting means alternating feeding and fasting periods with a goal of extending the fasting portion to stimulate positive hormonal changes. For health and fat loss purposes, a period of 16 to 24 hours is the most common.
In addition to eliminating bread completely, I would say Intermittent Fasting is the best thing one can do to improve their health. Going without food builds resilience. It toughens you up. You will conquer your fear of hunger. Hunger becomes preferable to poor food choices. The confidence you build from controlling your hunger will spill over into other aspects of your life.
My Intermittent Fasting mentors are Arthur De Vany and Brad Pilon. If you are interested in learning more about the science of IF, I highly recommend the e-book Eat Stop Eat by Brad Pilon. I bought it in 2008 and read it twice. It really helped me understand how the human body responds to fasting.
In the post Leanness Defined, I went over the 4 Levels of Leanness defined by Christian Thibaudeau and Chris Shugart. I also added a level. They are:
Level 0 – You are mostly lean, but your abs arent quite flat.
Level 1 Flat stomach with no ab definition.
Level 2 Level 1 + some upper ab definition.
Level 3 Level 2 + lower ab definition.
Level 4 Level 3 with deep cuts and dry (no water weight)
Moving to Level 1 Leanness
This is the most straight forward. As you get leaner you will see everything tighten up. I was at Level 0 Leanness from basically the 9th grade until 2 years ago. In order of importance, here are the steps I took to get to to Level 1 Leanness.
Reduced carbohydrate intake. Cut the sugar, bread and alcohol.
I was already doing the weight training, so really it was the first three items on the list that made the most difference. Note that nowhere on the list did I say go jogging, biking or spinning. The role of exercise in fat loss is way over stated. You are far better off spending your time in the kitchen cooking. Lift something heavy for 20 minutes a week and then focus your effort on food.
Moving to Level 2 Leanness
Going from Level 1 to Level 2 is like flying a plane in a storm. You can’t see where you are, so you have to trust your instruments. I’d like to quote Canada K, who I introduced in the post 17 Lessons For Fat Loss. He refers to this period as the Fat Loss Dead Zone.
Once you slide below 15%, the returns really diminish. You can lose a boatload of fat and it seems invisible. Its not until you get below 10%, or even 8%, where abs start to appear, where your waistline starts to get really tight, and where veins really start to show up.
So basically, there is this giant dead zone in the middle where youre making real gains but theyre incredibly unsatisfying. You must hang in there anyway. If you dont, youll never be lean.
This was an important lesson for me to learn. Going from Level 0 to Level 1 is highly rewarding. Every month you get a little but leaner and your clothes feel a little looser. This isn’t true for the journey from Level 1 to Level 2 Leanness. You’ll start to doubt your plan and be tempted to try new tricks, but patience is rewarded if your plan is solid. One day you’ll see your upper abs. Although I followed the same core principles as stated in the Moving to Level 1 Leanness, I added a few to assist with the process.
Improve Omega 3- Omega 6 ratios. I only eat 100% grass pastured animals or seafood and I stopped consuming seed oils.
Omega 3 fat cells are elongated and flexible, which places the hormone receptors on the exterior of the cell facing outward. This allows them to interact with hormones that trigger fat loss. Omega 6 fat cells are less flexible and have the hormonal receptors facing inward, which makes fat loss more difficult. Fixing your n-3 ratios is not something you can do overnight. It can take over 2 years to make the correction. Restaurants are notorious for using factory farm meat cooked in seed oils. You’ll need to source and cook your own food.
I reduced my caffeine intake so I am now sleeping a 8+ uninterrupted hours a night. Sleep helps you target fat loss over lean muscle. When I lived in DC, I would wake up at 4:45 AM and go to the gym. Sleep deprived and tired, I would eat carbs all day. I was never in worse shape.
Improving your gut flora can help you lean out. From the excellent post A healthy gut is the hidden key to weight loss by the Healthy Skeptic:
Other studies have shown that changes in the gut flora can increase the rate at which we absorb fatty acids and carbohydrates, and increase the storage of calories as fat. This means that someone with bad gut flora could eat the same amount of food as someone with a healthy gut, but extract more calories from it and gain more weight.
What have I been doing to improve my gut flora? Eating raw kimchi almost daily.
I have no way to measure the effect of cold weather training, but since it has become a daily part of my life, I feel I need to include it on the list.
Moving to Level 3 Leanness
I have yet to hit Level 3 Leanness. This is the stubborn fat. It has been camped out there for decades and it doesn’t want to leave. I don’t expect it to go easily. I mostly believe that Level 3 Leanness will come by following the same strategies I used to get this far. I’ll be patient and keep plugging away.
Soon I will be posting the winter version of Fall Strategies For Nutrition and Fitness. I believe winter is the optimal season for fat loss.
Moving to Level 4 Leanness
That topic is covered in detail in the article Shredded in 6 Days by Christian Thibaudeau and Chris Shugart.
Last Words
This is just a reminder that I am not a certified personal trainer or nutritionist. I’m just a hobbyist in the art of physique hacking. There are many paths to leanness. This post details what has worked for me.
Does Leangains intermittent fasting work? Yes, intermittent fasting helps you gain muscle and lose fat
but the reason why it works is unclear. It’s also unclear if it works
better than other nutritional programs – maybe, maybe not. What IS
clear that more basic research is needed. So, cut to
the chase, do I recommend that you follow Leangains style intermittent
fasting? I would say “Yes” if you are sure it’s the best thing since
sliced bread and “No” otherwise. If you are unsure, I recommend my top-down bodybuilding nutrition
approach. I will also continue to recommend 3+ meals a day because I
believe (but cant prove) it is a great tool in satisfying hunger with
fewer calories as well as a great aide in maximizing muscle gain. I
would also say it’s far more important what and how much
you eat than when you eat it or in how many meals you consume it in.
Beer and protein shakes at the “right time” is far inferior to a big
pile of vegetables and a chicken breast at the “wrong time”.If you want
to do intermittent fasting, I recommend the book Eat Stop Eat.
The Hodgetwins have made Martin Berkhan’s Leangains Intermittent Fasting (IF) program even more famous. Is the incredible buzz about intermittent fasting deserved? In this article, I give you my un-biased opinion on what intermittent fasting is, if intermittent fasting works, and why it works.
For those of you who won’t read this whole article, let me give you the conclusion first. The Leangains intermittent fasting program will definitely help you gain muscle and lose fat, the question is why and whether it’s really works better than any other training and nutrition methods. If you want to know more, I suggest you get the book shown on the right, Eat Stop Eat. I know I say this all the time but I will say it again:
“Bodybuilding is not an exact science, you need to experiment and find what works best for you” – Scooby Werkstatt
There are an incredibly complex array of factors that goes into determining what workout style and nutritional style will be best for you. The only thing for certain is that it probably wont be the same as for the guy standing next to you at the bench press. For some people, P90X, Insanity, or Crossfit works the best. For others, 5×5, SS, or a bodybuilding style workout like my home workouts give them maximum results.
It’s all about finding what works for you and helps you achieve your goals. Nutritionally, many people find eating frequent, smaller meals too stressful and time consuming – for them intermittent fasting provides optimal results. Others find that frequent small meals help them keep hunger at bay with fewer calories so they can lose fat and get ripped easier. Again, find what works best for you.
“It’s far more important WHAT you eat and HOW MUCH you eat than WHEN you eat it.” – Scooby Werkstatt
Although I am still recommend to people that they frequent small meals, I would much rather someone eat just two healthy meals a day in an intermittent fasting protocol than eat five meals consisting of BigMacs! What you eat is far more important to your success in health and bodybuilding than when you eat in my opinion. If you do follow intermittent fasting, remember that your work does not stop when you decide to constrain eating to an 8 hour window. The biggest nutritional task for any bodybuilder is deciding what to eat.
What is Intermittent Fasting?
Intermittent fasting is just like you would expect from the name. There are many other kinds of intermittent fasting, like alternate day intermittent fasting, but I will focus on the kind that Martin Berkhan at Leangains presents which is intra-day fasting – basically extending the night time sleeping fast a bit longer. Normal people fast for 8 hours during sleep and then eat for the other 16 hours. In the leangains intermittent fasting program, it’s the other way around – you fast for 16hrs and eat for 8 hours. If Leangains was just that the webpage would be just one sentence and we wouldn’t be talking about it now, Martin Berkhan’s Leangains website has hundreds of pages of information which I am going to try to boil down into a few bullet points below. I apologize profusely to Martin for this oversimplification of his program but for those unfamiliar with his program I need to give them a quick idea of what it involves:
Fasting 16 hours, eating window 8 hours long – number of meals irrelevant
TDEE +20% calories on lifting days, -20% on non lifting days. (TDEE is your Total Daily Energy Expenditure,if you eat at precisely your TDEE you will neither gain nor lose weight.)
Nutrition, consume at least 2.5g protein per kg of bodyweight
Intermittent fasting isn’t as new as it sounds, in fact it is thousands of years old. Ramadan is the most sacred month of the year for Muslims. During the month of Ramadan, they do not drink nor eat anything (nor sex, nor smoking either) from sunrise to sunset. This is a rather brutal type of intermittent fasting, brutal because the fasting period is during the day. Trying to concentrate and perform normally all day long without food is very, very difficult. If intermittent fasting by itself was the magical key to bodybuilding success then the pro bodybuilding contests would be won by practicing Muslims but this does not seem to be the case. In fact, a 2007 study of two Algerian soccer teams (practicing Muslims) showed that it significantly decreases athletic performance during Ramadan. As bodybuilders, this study is our first warning that we need to proceed very carefully with fasting.
Does Intermittent Fasting work? Yes, Intermittent fasting does work well for a lot of people. If you are getting good results from it then keep using it! You will note this is very similar to how I responded when people wanted to know “What Scooby thinks about YouTube trainer …” Before I take a critical look at Intermittent Fasting , lets look at why I make the above statements – I’m not being wishy washy. If intermittent fasting gives you the desired results, the reason *why* it works is irrelevant in my opinion. Intermittent fasting will help you gain muscle and lose fat if you believe it will. “WHAT?”, you say! Please hear me out. It doesn’t matter if it works because it is a superior program synergizing nutrition with Starting Strength workouts or if it works because of placebo effect.
Brain – Ally or Enemy?
The brain is the most powerful and important part of our bodies, it determines what you can and cannot do. If the brain in convinced that your life is in danger it will pump out adrenaline like a geyser and give you super-human strength. On the other hand, if you are pessimistic and convince your brain that you cannot do something then you will not be able to do it. If you make a P90X enthusiast do 5×5, I can guarantee you they will whine and complain the whole time and they will have very poor results. This is the reason it pays to have a positive attitude, there is something to it. In a very poorly understood process, if you believe that something will help you then it will.
Placebo Effect
This poorly understood process is called “The Placebo Effect“. The placebo effect is well documented in medical literature which is why all good research studies include a placebo group to make sure that the benefit is from the drug itself and not because the peoples brains have been fooled into healing them thru positive thinking. The term “placebo effect” is most often used when talking about drugs but it’s just as applicable when it comes to training programs. In my opinion, this is one of the reasons that there is so much heated disagreement from all the experts about what is the “best” training program. It’s because what is “best” depends on what the person believes is best. If someone is completely convinced that GOMAD and 5×5 is the optimal way to get stronger and more massive – then it will work! If it’s a reasonable workout strategy and you believe it will work, then it will give you great results. If you don’t believe your workout program is good then you wont have results no matter how well it works for everyone else. I am serious when I say that bodybuilding is equal parts mental and physical, leave out one half of the equation and you get poor results. When you choose a workout strategy, you need your brain as an ally – it’s gotta be 100% convinced you are doing the right thing. Work against your brain and it’s you are wasting your time.
Intermittent Fasting and Placebo Effect
So what does all this have to do with intermittent fasting ? I think you see where I’m going here. Since there is SO much buzz in locker rooms and gyms across the world about the leangains intermittent fasting program, a lot of people are totally convinced it will give them the results they want. Since their brains believe this, it WILL work. When they believe in the program, they will workout more intensely, they will workout longer, they wont skip days, and they will be religious about their nutrition. The leangains intermittent fasting program has an incredible momentum behind it. This is why in my blogpost “What does Scooby think about ..” I say that if a program is working for you and giving you the results you want that it is absolutely the best for you – no matter what it is. If intermittent fasting works, does it really matter *why* it works? Does it matter if it’s placebo effect or if their is some magical synergy between intermittent fasting and Mark Rippetoe’s SS style workouts?
The Newbie Effect.
This is a good time to point out that rank beginners to bodybuilding can do virtually any workout program, no matter how stupid, and get stronger and more massive. They can also use any nutritional program, no matter how stupid, and get stronger and more massive. Rank beginners can do the “curl monkey workout” where every day they do 100 curls and 100 pushups and have great results. The reason this is important to bring up is that as you will find in the following critical look at intermittent fasting, there is a severe lack of applicable, well done research – almost none. With a lack of good research, all workout programs (mine included) resort to anecdotal short term “before and after” comparisons are used and these folks are often beginners. A great before and after of a beginner on my website is just as useless as one on the leangains website. What matters is, can an advanced bodybuilder overcome a false genetic limit and make further gains with the workout system and what is the maximum that someone can achieve on the program.
Recompositioning.
Leangains program seems to be associated with the term “recompositioning” in peoples minds. What is recompositioning? It’s what I have always referred to as gain muscle and lose fat at the same time. Every day on bodybuilding forums across the world people argue about whether bulking and cutting is the fastest way to a ripped, muscular physique or if recompositioning is. Many bulker/cutters seem to think that *everyone* has to bulk to gain muscle but the success stories pages of P90X, my website, and the leangains website suggest otherwise. Remember what I said earlier, that beginners and intermediates can do virtually anything and make good gains? From everything I have seen, beginners achieve their goal of obtaining a muscular, lean physique much faster with a recompositioning type nutritional program (set goal = recomp on my calorie calculator) than with bulking/cutting. This is true for many intermediate bodybuilders as well. It’s my experience that only when you get to within 20% of your genetic max that you need to start playing tricks with your body, like bulking/cutting, to coax out further gains. Leangains and I are in complete agreement on this issue, recompositioning is the way to go for beginners and most intermediate bodybuilders – in other words, workout hard while eating at your TDEE. If you are obese, then perhaps eating 5-20% under your TDEE is called for depending on your level of obesity. For advanced bodybuilders, that is, those within 20% of their genetic potential it appears that bulking/cutting is the way to go.
Examination of Intermittent Fasting.
First it’s important to ask, does intermittent fasting work for *what*. What is the criteria that we are judging intermittent fasting on? Gaining muscle? Losing fat? Athletic performance? Endurance? Disease prevention? Reduction of cancer risk? Improved cardiovascular health? Better health markers (blood pressure, lipid levels, etc). Since most people here are young and healthy and are only concerned with the cosmetic aspects, we will stick to those: strength gain, mass gain, and bodyfat reduction.
Often in bodybuilding, arguments about nutrition or lifting programs turns into a ping pong match where the opponents take turns sending research volleys over the net to the opposing team where they point out the faults of the study which render it useless then smack their research paper over the net which ‘proves’ their point – and the game continues. At the end, if both players have the hundreds of hours at their disposal to find, read, and analyze the research, the game ends in a draw with both players exhausted both admitting that their needs to be better research done. In my opinion, this is basically what has happened with intermittent fasting between Alan Aragon and Martin Berkhan. I’m not going to re-invent the wheel here nor am I going to pretend to know as much about nutrition as Alan aragon. If you want to see the definitive critical analysis of intermittent fasting based upon research, then see Alan Aragon’s An Objective Look at Intermittent Fasting. Alan Aragon is one of the top bodybuilding nutritional specialists in the world and he makes a living doing unbiased, critical analysis of published researched papers with a bodybuilding eye. If you argue with Alan’s opinion then you had better have done your homework and have a stack of research to back you up. If you don’t read his whole paper, please read at least the conclusion. I don’t want to copy it here but I think I can safely include one sentence from the two paragraph summary that gives the flavor of the whole paper without stepping into copyright issues:
“In the world of fitness, recommendations for improving performance and body composition often gain blind acceptance despite a dearth of objective data.”
In an objective review of intermittent fasting, thats not a very positive outlook! OK, so lets look at some of the main points of intermittent fasting.
Health.
I know most are not interested in the health aspects of leangains intermittent fasting program but I have some big concerns about it so I will cover it quickly. A bad omen is that as far as I can tell, the words “vegetable”, “fiber”, and “anti-oxidant” do not seem to appear anywhere on the leangains website but there is a whole section on supplements. I’m a bit concerned about what the people following the Leangains program are actually eating. As far as the health of the intermittent fasting itself. It does appear the following the leangains intermittent fasting program does improve your cholesterol levels but according to this study, it appears that the same benefit can be achieved by exercise alone. The other concern I have about the health aspects of the leangains program is that it does not include cardio. In my opinion, daily cardio is the kernel of any fitness program that has overall health and well being as a goal.
Performance.
By performance I mean strength, endurance, speed, balance, and coordination. The before mentioned study of Algerian soccer players during Ramadan clearly showed that Ramadan style fasting is detrimental to performance. What about leangains style intermittent fasting, is it detrimental to performance? We don’t know as there is no research other than the soccer study. It’s clear that Ramadan style fasting where no food nor beverage can be consumed during the day has a far worse effect on performance than leangains style intermittent fasting where eating can happen 8 hours during the day. So leangains style intermittent fasting isn’t as bad as sunrise to sunset fasting on performance but is it still a problem? My guess is it depends on when the athletic event is. If the athletic event falls in the feeding window like a football practice would, my guess is that there is no performance degradation at all with leangains intermittent fasting. On the other hand, if your athletic event occurs during the fasting window then I’m willing to bet there is a significant performance degradation. Research done by Bird points to me being correct in this assumption. There are many anecdotal reports of people “having so much energy” in the morning before they eat. To those people I say, “see you at the race”. If you have so much energy while fasting lets do a Half Ironman and see who wins – you keep fasting during the race and I get to eat my normal 5000 calories or so in energy drinks, gels, and bars. Well see how much energy you have then As I discuss in when to do cardio, I personally find that when I attempt cardio before eating in the morning my cardio session is much shorter than if I do it after a small meal. What works for me is to eat a small well balanced meal and then exercise.
Ability to Lose Bodyfat.
Lets start with something that is very clear. Meal frequency does not affect how many calories per day your body burns, your total daily energy expenditure (TDEE). If the number of calories is the same, it doesn’t matter if you consume then in one large meal a day or ten small meals a day – your TDEE remains constant, as long as they are regularly scheduled meals. It does appear that an irregular feeding schedule can decrease your metabolism and make losing fat harder but nothing increases it and makes losing fat easier.
What about decreasing your feeding window from the normal person’s 16 hours to a leangains intermittent fasting participant’s 8 hour feeding window, does that make losing fat easier? Let the ping pong match between Alan Aragon and Martin Berkhan begin! As far as I can see, all the studies used when talking about this are seriously flawed and both sides agree that more research is needed.
According to Alan Aragon, the main study used to show the benefits of intermittent fasting has a number of serious flaws and I agree with him. There were only 20 participants and 5 dropped out which most likely means those 5 participants were having poor results. Leaving out all the people who have poor results out of the study doesn’t make it much of a study does it? The other huge problem is that they used a very inaccurate method for determining body composition, basically just measuring body impedance as the cheapo digital bodyfat tools do. Couple the inaccurate body composition measurements with the extremely short study period (6 weeks) and you get questionable results at best.
It’s clear that many, many people have gotten muscular and shredded from the Leangains style intermittent fasting. The question is why. Let me bring up something related, carb cycling. It’s clear that carb cycling works great but it’s very complicated to make a meal plan (which is why I made my automated carb cycling meal planner) so anyone who does carb cycling is making a huge commitment.
Does carb cycling work because there is some biochemistry behind it or does it simply work because it’s followers watch their macros and calories so carefully as the old admin of the AskScooby forum suggested? It’s pretty clear to me now that he was right, it’s not carb cycling that makes you ripped quickly without losing any muscle mass, it’s the fact that you get plenty of protein, lots of vegetables, enough good fats and EFAs, and run a tightly monitored caloric deficit. The same question applies to intermittent fasting, is something inherent in the intermittent fasting itself that makes losing fat easier or is it just the fact that you are paying more attention to your nutrition? Again, I ask the question – does it really matter if it works? No! Leangains intermittent fasting works for many people in helping them get ripped while gaining strength and muscle mass so who cares why? So does intermittent fasting help you lose bodyfat? Maybe, maybe not. What is clear is that more research needs to be done.
Ability to Gain Muscle.
So, will leangains style intermittent fasting help you gain muscle? As far as I can tell, Martin Berkhan’s Leangains program recommends that you follow Mark Rippetoe’s Starting Strength (SS) program. Yes, of course! Following Mark Rippetoe’s lifting program while following Martin Berkhan’s leangains intermittent fasting program WILL make you bigger and stronger. A number of questions arise though. First, is SS the best choice for you based upon your goals, age, and limitations? Second question which is more important, is it the SS alone giving Leangains participants their mass and strength gains or is it a symbiotic relationship between SS and leangains IF that causes some amplification of results? If you did a year long study of SS+IF vs SS+GOMAD, who would have the better muscular and strength gains? If SS+IF produces better results, is that because IF people on the whole are more educated about nutrition than GOMAD folks? So then you have to do another study, what if everyone did GOMAD and SS but half the group did GOMAD in the intermittent fasting style? You will see here that we have far more questions than answers. As far as I know, there has been no study to date that shows you can gain muscle mass and strength faster with an intermittent fasting protocol than with normal eating.
Summary
Does Leangains intermittent fasting work? Yes, intermittent fasting helps you gain muscle and lose fat but the reason why it works is unclear. It’s also unclear if it works better than other nutritional programs – maybe, maybe not. What IS clear that more basic research is needed.
So, cut to the chase, do I recommend that you follow Leangains style intermittent fasting? I would say “Yes” if you are sure it’s the best thing since sliced bread and “No” otherwise.
If you are unsure, I recommend my top-down bodybuilding nutrition approach. I will also continue to recommend 3+ meals a day because I believe (but cant prove) it is a great tool in satisfying hunger with fewer calories as well as a great aide in maximizing muscle gain.
I would also say it’s far more important what and how much you eat than when you eat it or in how many meals you consume it in. Beer and protein shakes at the “right time” is far inferior to a big pile of vegetables and a chicken breast at the “wrong time”.If you want to do intermittent fasting, I recommend the book Eat Stop Eat.
and saving all your carb consumption for post workout. 
which we know is a stress hormone rises while we sleep, and for most people on a regular schedule it peaks in the early morning around 7am. 
As I discuss in 
