Tuesday, April 27, 2010

Intermittent Fasting: To Feast or Not to Feast

New interview at Elitefts. Intermittent Fasting — to Feast or Not to Feast: An Interview with Martin Berkhan.


LayzieBone085 said...

Outstanding article as always Martin. I appreciate the time you put into interviews, writings, and your upcoming books :)

Moz said...

Good interview but confused about the project w/ Lyle and company. I was under the impression that that was no longer happening. Is the interview old or is my information wrong?

Martin Berkhan said...


Thanks, glad you liked it.


Interview was made before we decided to cancel the project.

Name: Zach Porcher said...


Just wanted to say I absolutely love the site and because of you and a few others I am convinced of IF and its benefits both in and out of the weight room. I am going on 10 weeks now and have never felt better in my life. Elite is a great website, really cool to see your approach and IF in general getting exposure on major lifting websites.

Chino said...

Thank you for sharing Martin, I wasn't aware you were working on two books. Martin and Lyle, what a fucking combo! Love it, keep up the good work.

PS: I am trialing IF (on low carb) on Wed which are my rest days (LISS first thing) and so far it's working well. Not hungry, LISS was easy, and currently on the 13th hour. IF seems to be very doable.

Martin Berkhan said...

We're not. We cancelled the project. The main reasion being that we didn't think it would be a great idea to have four different methods in one book. It would only confuse people.

Martin Berkhan said...


Thanks, glad to hear it.

Chino said...

Ah, thx for the clarification Martin.

Anonymous said...

Martin, I wanted to give you and your readers an update on my first 9 days on IF. I've been dieting and working-out for years without much progress (after losing 120 lbs). I stalled with bodyfat around 16-18% and want to get down to 10%. (I'm 40.)

My IF approach is a little extreme right now including 3 24 hr fasts per week:

Monday: 24 hr fast (no training)
Tuesday: 17 hr fast / 7 hr feast (training 7PM)
Wednesday: 24 hr fast (no training)
Thursday: 17 hr fast / 7 hr feast (training 7PM)
Friday: 24 hr fast (no training)
Saturday: 16 hr fast / 8 hr feast (fasted training @ noon)
Sunday: 17 hr fast / 7 hr feast (no training)

So every two days I fast 41 hours, eat 7 hours, and train once.

After 9 days, I went from 225 to 219 (I'm 6' 2" and have a moderate amount of muscle) and my waist went down 1 inch! (And these were newbie gains. I was already seriously dieting and training before starting IF.)

I know the amount of fasting I do is extreme. I will probably only do this for a couple more weeks and then transition to your traditional 16/8 daily fasting/feeding plan. The risks of my extreme approach are: catabolism/muscle loss and messing with the timing of my ghrelin pulse. What are your thoughts on these risks?

I was worried about hunger. But I actually feel great even at hour 40 of each fast. I get a little nauseous mid-morning (especially the morning after the 7 hour feed) for about 15 minutes. But I know it will soon pass. Carbonated drinks help the hunger.

I tried fasted training on Saturday around noon after fasting for 36 hours. I thought that I'd feel weak and might even pass out. But I felt great and my lifts were higher than my previous workout.

I'll keep you updated on future results.

I can't see giving up IF any time soon. I wish I had found it years ago. I would have saved a lot of wasted effort. Thank you , thank you, thank you.

By the way, I sent you an e-mail asking to hire you as consultant. How long is your waitlist?

alexw said...

so i fully understand the dieting, IF aspect of your posts. Where would you guide someone, on your site or others, who is looking for specifics on lifting approaches? Reps, volume, intensity, etc.
Like many of your readers, i am a young, lean, athletic male who already has a solid background in weight training.

'miss said...

How much does it cost to have you as a coach?

Haley said...

Great interview. You didn't mention anything about women and the fast. Do you still suggest the 14 hour fast for us, or should we work up to the 16 hour fast?

Thanks again for great info!

Seve' said...

Another candid yet informative interview/article, Martin.

Can you share your findings of effectiveness between high volume workout vs low volume/high intensity?

Would you consult differently based on current conditions of your clients now that you have more infomation?

Btw, I just announced to my family members that I would be doing IF for life not just a diet attempt anymore. I feel that this 16hr IF is very easy to do and found very flexible.

Thanks again, Martin for sharing this info and enhancing our lives.

Moritz said...


Well, that was easy...

Anonymous said...


Thank you for continuing to hand out great information. I'm sure it will only help increase the anticipation for the release of your book (which I will get the moment you'll release the damn thing).

Looking forward to your article on early morning training, since that is what I currently do. I thought that it would be a bad idea to go without food after some serious weight lifting so I opted not to IF on workout days. I'm hoping you'll present a different way to go about things.


gbloomer said...

Another great interview and read Martin! I love the straight talking approach you adopt. Gets to the point. The comment from Seve made me laugh when he said about announcing IF for life to his family. Reminded me of a conversation with my wife when I told her this was the way I planned to continue with my eating habits. She said that Northern Ireland couldn't hold out to the amount of animals I am consuming in a week! I think I will email this interview to her at work and maybe she can get a grasp of it and understand IF a bit more.

Anonymous said...


short question, do you ever train your abs?can you get AMAZIN abs with just low enough body fat ?
thx :D

Jason said...

Found your interview very helpful. I always have a tough time with my diet.

John said...

I've been trialing Lean Gains (if I may call it that since I wasn't counseled by you) for two weeks and the results are so good I'm making a definite switch to this permanently. I appreciate your work very much and I'm thankful for this revelation.

I'd like to ask something if it's not too much trouble. In your transformation article you said that you drastically increased calorie intake when you went on a Lean Gains bulk. Does this mean that while bulking both your training and rest days became hypercaloric or did you just further increase calories on training days while still leaving rest days mildly hypocaloric?


Martin Berkhan said...


'catabolism/muscle loss and messing with the timing of my ghrelin pulse. What are your thoughts on these risks?'

The longer the fast, the greater the risk of muscle catabolism. After 16 hrs blood sugar is maintained mostly by gluconeogenesis from amino acids (as opposed to stored glycogen in the liver).

This doesn't necessarily mean that net muscle catabolism will occur. If your last meal is substantial enough it will carry you several hours into the fast. Provide a steady trickle of amino acids into your blood stream. These aminos can be used for protein synthesis and gluconeogenesis as opposed to amino acids having to exit muscles during the fast to become substrates for gluconeogenesis.

But 41 hrs is quite a lot. There's actually a study out there showing that gene expression for proteolysis is switched on after 40hrs or so.

But if you're not losing any strength, its a pretty good indicator that you're not losing any muscle. Its hard to give any clear cut answers. Many factors play a role: your last meal, your body fat percentage etc.

Martin Berkhan said...


See Training.




Still 14 hours. But a lot of women do great with 16 hrs as well.


'Can you share your findings of effectiveness between high volume workout vs low volume/high intensity?'

I will do that some time, yes.

Martin Berkhan said...


Sounds good. But I've yet to come across someone outside of internet forums that wasn't convinced that six meals a day boosts metabolism, insulin is evil, carbs are fattening etc. Explaining IF to someone with a poor or average understanding of nutrition is usually a waste of time.

Martin Berkhan said...


No ab-training. And yes, you can get good abs without training them directly. Compound movements like squats, deadlifts and chins all work the abs just fine.

Martin Berkhan said...


Thanks, I'm glad you find my system so effective.

On my very first bulk done IF style I kept all days hypercaloric.

Anonymous said...

Martin: "But 41 hrs is quite a lot. There's actually a study out there showing that gene expression for proteolysis is switched on after 40hrs or so. But if you're not losing any strength, its a pretty good indicator that you're not losing any muscle."

I know three 41-hr fasts per week is a lot; maybe too much. I'm just doing it as an experiment for 2-3 weeks. I'll see if the fat loss is good and if I retain my strength. I'll probably switch back to your standard 16/8 daily plan after the experiment is over; though eating EVERY day seems like so much food now!

For the rest of the experiment though, should I eat 2 days' worth of calories pre- and post- training if I fasted 41 hrs before or should I just eat 1 or 1.5 days' worth? (I'm trying to lose fat, so my target calories are 500-750 below maintenance.)

Martin Berkhan said...

'For the rest of the experiment though, should I eat 2 days' worth of calories pre- and post- training if I fasted 41 hrs before or should I just eat 1 or 1.5 days' worth? '

This question hurts my brain. If what you have been doing is working well, which seems to be the case, then don't change anything.

Seve' said...


I went back to read some of your older post like "minimalist."

As I stated, according to Body By Science(HIT approach), I do 1/wk 10~12 minutes to failure whether Big5 or Big3. In 17 weeks, I've lost 13.5 lbs and 5%BF.

From my detailed notes, I fear my strength/wt load and fat loss have come to a hault. All of weight seems to be bodyfat, yet I have gained tremendously in strength, especially in Leg Press.

Where would I go from here to add muscle/fat loss?

Martin Berkhan said...

Well, first of all you should read the last section of the Leangains Guide. And then you should consider that you won't be able to increase strength/muscle indefinitely on a hypocaloric diet. Which to my understanding is what you have been doing so far.

Anonymous said...

Great interview and great blog. Will most def give IF/Leangains a solid trial later this year.

Tom said...

Thumbs up Martin.

Anonymous said...

Nothing to do with this text, but it's just a quick question.

Do I need military press or will bench press/leteral raises keep my shoulder muscles while cutting?
I'm asking, because my right shoulder don't like military press.


Martin Berkhan said...

Very likely, yes. I've cut down just fine without any direct shoulder work and those muscles were maintained just fine. The shoulder muscles are involved in many compound movements - bench, chins, deadlifts etc.

Cole said...

Martin i think I.F is pretty cool and unique. I have one question though, What do you say to the people who support the idea of regulating the glycemic index / load of the foods to where you stay below a certain G.I/G.L level or whatever each meal? I ask because there is no way I.F could follow this.

Martin Berkhan said...

Blood glucose is always maintained within a tight interval with the exception of the post-prandial phase (after meals). Unless you're eating highly refined carbs/junk and/or are metabolically impaired in some way there is no rationale for being concerned about GI/GL.

Cole said...

following up on that last question about GI i am confused about just one thing.
Say i wanted to do without the fast for some reason (just eat 3 meals a day).. Am i not going to loose fat because the only time you loose fat is during the fast because there is no insulin raise? and that when you have your feeding window your insulin is higher so you arent loosing any fat then?

question in short- with a very basic 3 meals a day type template is it much harder to loose fat because your insulin would be raised for most of the day? or like you said the GI/GL doesnt have a high enough impact to raise it any substantial amount?

sorry for a super long, kinda repeptitive question. its just hard to find a credible answer on the net (besides this haha).

Martin Berkhan said...

You'll lose fat if you maintain a calorie deficit regardless of diet composition. Insulin is not the sole determinant fo fat loss.

High fat diet = high fat intake, high fat oxidation, low insulin. A lot of fat is burned, OTOH a lot of fat is consumed.

High carb diet = low fat intake, low fat oxidation, high insulin. Fat oxidation is low, but OTOH not a lot of fat is consumed.

Whether fat balance is positive (fat is stored in adipose tissue) or negative (fat is released from adipose tissue) at the end of the day ultimately depends on your calorie intake.

Cole said...

Thanks Martin. i'm a bigger eater so i'm excited to try some of these methods out as soon as i can

Body By BB2K said...

I train at 9am usually. How do I make this work for me? Train on an empty stomach then head home and eat my pwo meal then wait another 8 hours and eat again?

My name is Martin Berkhan and I work as a nutritional consultant, magazine writer and personal trainer.

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