Thursday, October 29, 2009

Questions & Answers

This is the first in a series of posts with the most useful replies I made in the íntermittent fasting thread on Answers have been edited/updated when needed.


Calorie Restriction (CR) vs Intermittent Fasting

Q: I think CR in general is probably more healthy for some people than "fasting".

A: Depends on how you define "healthy". The whole premise of CR for life extension may sound great on paper, but it's not much fun to chronically restrict calories for rest of your life in order to live a few years more. Especially if the price you pay is hunger and weakness.

Studies hint that IF may have life extension benefits on it's own, some of them are unique to IF and not seen with CR: disease prevention, protection against brain disorders (i.e Alzheimers), immune system support and improved pulmonary function, even on higher calorie intakes.

IF at energy balance > CR.

So perhaps we can get all the benefits of CR, and then some, without having to restrict intake as harshly. Here's an example of some of the exclusive benefits of IF vs CR;

"...Nevertheless, intermittent fasting resulted in beneficial effects that met or exceeded those of caloric restriction including reduced serum glucose and insulin levels and increased resistance of neurons in the brain to excitotoxic stress. Intermittent fasting therefore has beneficial effects on glucose regulation and neuronal resistance to injury in these mice that are independent of caloric intake. "

From "Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake" by Anson et al.

Then again, it may be wishful thinking. Main support for the hypothesis comes from animal research, human research is still sparse. However, there are some recent studies that lends support for the hypothesis to be valid for humans as well, for example:

"...These findings demonstrate rapid and sustained beneficial effects of ADCR on the underlying disease process in subjects with asthma, suggesting a novel approach for therapeutic intervention in this disorder. " (the authors conclude that alternate day fasting > CR)

From "Alternate Day Calorie Restriction Improves Clinical Findings and Reduces Markers of Oxidative Stress and Inflammation in Overweight Adults with Moderate Asthma" by Johnson et al.

The mechanism by which fasting protects the heart is not known, but may involve an enhanced ability of cells to cope with oxidative and metabolic stress. Wan et al speculated that...

"A recent study showed that alternate-day caloric restriction can reduce systemic markers of inflammation and oxidative stress and can reduce symptoms in subjects with asthma" (Here they are referring to the human trial by Johnson et al)


"Intermittent Fasting imposes a mild beneficial stress on cells."

And affects adiponectin:

"Adiponectin concentration was twofold greater in the plasma of rats that had been maintained for 3 months on the IF diet"

Conluding that Adiponectin may possibly explain some of the beneficial effects:

"Adiponectin has previously been shown to have cardioprotective and anti-inflammatory actions. "

Yet finishing with some reservations, as the research is still scarce on this topic:

"IF results in changes in levels of several circulating factors including decreased levels of insulin, leptin and cholesterol, and increased levels of testosterone [27]*. It will therefore be important to elucidate the roles for, and interactions, of these different factors in cardiovascular responses to IF. "

* The effects on testosterone seems unique to rodents so far (personal conslusion based on my review of the topic).

The above is from "Cardioprotective effect of intermittent fasting is associated with an elevation of adiponectin levels in rats" by Wan et al. A recent paper discussed the cardioprotective benefits with regards to humans:

"Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults" by Varady et al.


I wrote the above almost two years ago (added some recent studies for the sake of context). Since then, there's been some additional findings, though nothing groundbreaking. There's a lot on this topic, but I'm gonna cut it short here. Have written plenty on this in the book. To summarize my response to the question: intermittent fasting may or may not have exclusive benefits which cannot be obtained with a traditional, calorie restricted diet. However, due to the scarcity of research on humans, and due to many confounders present in the available research (i.e some of the studies on IF/ADF does not use a CR control group), it's hard to say anything for certain yet.

Intermittent Fasting and PPOS

Q: The Life Extension Foundation is big on the idea that big meals = elevated post prandial oxidative stress (PPOS) which is obviously a negative. Any opinion on this seemingly negative effect of IF/Big Meals?

A: Studies* show oxidative stress is less on intermittent fasting compared to regular calorie restriction. Yes, even when comparing the same calorie intake with varying meal splits (i.e 3 big meals vs 6-9 small meals). The neuroprotective effects of the fast yields the net effect of PPOS being lesser on IF - despite larger meals.

* in ref to Anson et al.

Catabolism during the fast

Q: So, how long does it take for significant muscular catabolism to start? Over 24 hrs?

A: That's context dependent, but consider that blood glucose is maintained within range mostly by gluconeogenesis beyond the 16 hr mark*. That answer might not make a lot of sense, but eat sufficient amounts of slow releasing protein before going to bed and it shouldn't be an issue even if you go for longer than 16 hrs.**

They key factor in whether you'll lose muscle or not is the severity of calorie deficit, not meal time intervals within a non-retarded range.

* note that the studies looking at this contained nutrional regimens very different from what we are doing (i.e Cahill et all fed test subjects 100 g cho before bed time, no protein, and then had them fast for several days to gauge the rate by which liver glycogen vs gluconeogenesis contributes to maintain blood glucose).

** hell there's even a study out there suggesting proteolytic gene expression does not become turned on until the 40 hr mark or so.

A more recent question on the same topic -

Q: Hey guys, got a question about fasting length. I'm currently IF'ing by doing two 24 hour fasts per week (two days with complete fasting) My question is, could I do both fasts consecutively and do one large 48 hour fast? What is the longest amount of time that it is safe to fast before LBM loss/metabolic downregulation?

A: Safest? Well, consider that de novo gluconeogenesis escalates beyond 16 hrs. 16 hrs is the tipping point - your glucose demands after this point is met primarily (more than 50%) by conversion of stored amino acids into blood glucose. Liver will support the brunt of glucose needs before that point. Theoretically, proteolysis will occur to the greatest extent 24-48 hrs into the fast. Of course, there are numerous confounders here to take into account (i.e a casein heavy meal before the fast will delay proteolysis further).

Metabolic downregulation? Up to 72 hrs according to most studies.

Saturday, October 24, 2009

Some pics

It's been a while now, so here's a few recent ones.

This is more or less the condition I maintain at all times of the year. Weight is approximately 195-200 lbs. I'm not sure of the exact number, since my scale is broke.

Wednesday, October 21, 2009


I get these e-mails from time to time and it's always a pleasure to read them.



after all the knowledge I have gathered through your site, and from your articles I decided to give this a go when i started a mini-cut.

After 5 weeks of mini-cutting I went from 167.5 lbs to 160.7lbs, Most of the loss would be fat throughout the entire process. Following the IF principles was cake, after day 1-2 the hunger cravings were non-existant, and everything was smooth sailing.

Eating big, and letting the body recover while keeping workouts simple and to the point were nothing but a walk in the park. Intensity was high and energy was beyond belief.

I really cannot exaggerate how easy of a lifestyle this is to a college student who spends countless hours in the library, studying, and working to support the needs to complete a college career and get a job. After 5 weeks of attempting this on my own I am sold on your research, your lifestyle, and the way at which people have been doing this for years.

After reading your testimonials, responses, and following an individual on who was a client of yours I always wanted to give this a shot, and did not know if I could change from the whole 6 meals a day thing, I have always had thoughts and wanted to just eat a massive meal 2-3 times a day and call it quits. Well reality sunk in, I gave in, and it is something that has happened to work very well for me.

Here is a link to my workout journal, and I took two videos. One of Before, and One of after (from 9-14-09 to 10-19-09 (Today)) Showing the changes my body experienced while utilizing IF on a cutting diet. Calories never dropped below 2500 on workout days while off days were a touch lower with lower carbs (i know you advocate that). Based off what everyone has said about this lifestyle it came true for me.

I wanted to e-mail and tell you this, that if I do decide to do a contest in the future, I will need your assistance with dialing in my body for the final weeks and work my way towards placing in a bodybuilding show (a dream of mine).

Thank you for all of your advice on the forums. It is GREATLY appreciated, because half of the people on there dont know jack shit.

Best Wishes Always,

- Bob Kupniewski

The Link and the transformation videos after a 5 week IF experiment:

I hope you get some good feedback from this, and understand what you are doing is working, and the more you promote the greater of an individual you will become. Keep up the hard work."


By the way, I'm planning a "Best Of" post based on the long running intermittent fasting thread on It will contain expanded and updated answers to questions posted there, and should be a good complement to Questions and Answers on this blog.

Saturday, October 17, 2009

The Champ

I'm happy to announce that Andreaz Engström won the -70 kg class at the Nordic Bodybuilding Championships in Trondheim, Norway, today.

The competition pits competitors from Sweden, Norway, Denmark, Finland, Iceland, Estonia, Latvia and Lithuania against each other.

Third time's a charm, as the saying goes, and this has been an exciting journey for us both. Drawing upon experiences from his first two competitions, I managed to nail the final two weeks perfectly this time around. In combination with his flawless compliance, victory was achieved.

Monday, October 12, 2009

The Paleo Cookbook Book Review

Mission Statement: all reviews will be my honest assessment of the material in question. My opinion will never be influenced by personal bias or my opinion of the author.

The Paleo Cookbook

Recipes for the Paleo Diet - Two Cookbooks - 120 Recipes Each!

"These are the results my clients have experienced and that i have experienced as well - that's why I'm a huge advocate for the paleo diet and I believe you too can experience how amazing it is to suddenly be able to go through your days with more energy, while seeing a happier, healthier body in the mirror."

– Nikki Young

Who is this book for?

It’s for someone looking to adopt a healthy diet and maybe lose a few pounds in the process. The book may also be for someone with a special preference for paleo dieting or a person looking for some new meal ideas to add to their daily menu.

What will I learn from it?

You'll learn to cook and prepare a variety of paleo meals for different occasions.

Strong points

* It features a very extensive list of recipes. Seven books all in all; two main books, and five theme-based books (i.e chocolate and capsicum sandwiches). So in addition to meals that would make good diet staples, there are also paleo-based dessert recipes and snacks.

* Excellent layout with high-quality pictures for every recipe.

* Clear instructions on how to prepare the meals.

* Contains creative solutions to make paleo friendly versions of modern foods such as noodles and sandwiches.

Weak points

* I couldn't find any major flaws with this product. It delivers exactly what it promises. One drawback is that nutritional information is not listed for each meal, but that's not hard to look up yourself either. The book also contains some recipes with "forbidden" foods that might anger some of the purists but these did not bother me.


One of my clients swears by this cookbook, which was the main reason I wanted to read and review it. I don’t typically consider recipe books but I was pleasantly surprised by Young’s. It delivers what it promises and does so in a stylish way. The collection of recipes may be used whether one is dieting, bulking or just maintaining their physique.

I've tried about a dozen recipes so far, and they've all turned out well. My personal favorites are coconut chicken curry, white fish with almond and tomato sauce, and "kids" meatloaf (no idea how Young came up with that name). The coconut sorbet dessert was awesome. There's also a coconut chocolate cake I’d really like to try but I'll have to ask someone to make that for me. Baking is just too much for a simpleton like me. But I'll report back once I can bribe someone into baking it.

This book holds even greater value if you're following the paleo diet to a T, which I don't (nor does the author, according to an interview). Want a quick paleo snack? It’s here. Want’s a filling paleo meal that requires little prep time? It’s here. Want to impress someone with an elaborate paleo dinner? It’s here too. But regardless of your diet habits, the recipes in this book will keep you occupied for a long time, adding variety and flavor to your meals.

If anyone already has this book, or buys it, feel free to post your personal favorites in the comments section.

A quick note about paleo diets in general

There’s now research that supports the health benefits of a paleo diet. A recent study* showed participants’ health markers improved when they switched to a paleo diet for ten days. Most people will see benefits in these markers simply by making an effort to eat healthier, in which case the cause would be reducing calorie intake and the resultant weight loss.

This study was of particular note because calorie and macronutrient intake was controlled and set to maintain the weight of participants. The benefits seen – such as lower fasting insulin, improvements in insulin sensitivity and blood lipids – resulted from manipulating quality, not quantity, of foods in the participants’ diet.

Also these results were recorded after merely ten days of following the paleo diet, so they were seen without the confounding factor of weight loss. When it comes to health, the paradigm of "a calorie is a calorie" doesn't ring true. However, it isn't wrong to assume that similar results would have been obtained by following a regular "clean" diet despite what some of the hardcore paleo proponents may tell you.

* Frassetto, et al. Metabolic and physiologic improvements from consuming a paleolithic, hunter-gatherer type diet. Eur J Clin Nutr. 2009 Feb 11.

Tuesday, October 6, 2009

Best Comment So Far

This comment deserves a post of it's own. From comments in Randomness.

Mamaelvis -

"Maybe you know all of the following, but just in case it helps you. (It helped me)

Making a tiny insignificant commitment to writing for even 2 focused minutes everyday almost always leads to writing a hell of alot more at a sitting just out of momentum.

Keeping a visible calendar with your successful commitment's to those days reinforces that you are following through on your writing.

The other trick is saying to yourself that this is "only a rough draft" if you are stalling out of wanting that "definitive book" to fall out of you. It usually won't & even if it did nobody needs perfection.

Huge books about diet filled with theory & studies are usually summed up in less then 20 pages.

I think that your strength is that you were not a lean teenage person & you learned how to put yourself into a exceptional condition.

From what I can see from the whole of the internet, right now... you are doing this more successfully then anyone. (On a consistent basis with photo testimonials)

So from my point of view I hope your book will at least touch on the following (like your blog):

Emphasis on your decision not to become psycho about eating.

Your personal story as on the with photos of when you were chubby.

Variances in approach with different clients & why.

Documentation & photos from clients plans.

I could give a shit about studies to tell the truth.

The fact that you were fat & leaned out to the level you are now & doing the same helping your clients is amazing. I mean look at how many people fail at getting in shape & you are transforming people on a consistent basis.

What more do you need to write about? Possibly mental techniques for people who can't comply well?

Maybe stuff to build your own reputation to further your professional goals.

Put the book out! In the time you have started talking about intermittent fasting, so many people have jumped on the bandwagon & they really don't have the results you have already documented here.

Swedes are waaaaay to modest & perfectionistic.

C'mon kick some ass. You have an embarrassment of riches already compared to other fitness 'experts'"

My reply -


Thanks for taking the time to write this. Personally, I think this is the best comment on my blog so far.

Some very useful advice in here that I needed to be reminded of. You're right on all accounts regarding book writing and getting it done. I could have had the book out a long time ago if I wasn't so focused on some trivial aspects no one really cares that much about (with regards to studies on the topic). I'm a perfectionist when it comes to this, and it's certainly a double-edged sword in this business. Your post got me thinking. Thanks again.

Thursday, October 1, 2009

Magazine Article

No doubt, the six-meal-a-day-approach so prevalent among fitness professionals and recreational trainees alike can interfere with social life and work.

It's sad considering it doesn't have to be that way. Indeed we ourselves are the creators of all of our troubles and compulsions. But it certainly doesn't help when we are constantly showered with messages concerning the dire consequences of not eating every two to three hours. Nonsense and make believe.

But there is hope. I'm working with an ever increasing amount of competitors who are fed up with the old dogma and time-consuming behavior that tends to come with the territory. It's good to see and experience that more people in this industry are starting to open up their eyes. Role models are needed to create change on a greater scale.

Here's an article about one of my clients. I've translated some parts of it.

"...this summer I adopted an intermittent fasting regimen. It entails two large meals a day, and the approach fits me like hand in glove. As a bonus, I've gradually leaned out as well."

Note that Andreaz is eating two meals most days, while the default approach includes three meals. There are no set rules regarding meal frequency within the 8 hour feeding phase, but other clients tend to prefer three meals (as do I).

"As I received excellent coaching from Martin Berkhan during the pre-contest prep, I was very pleased with my conditioning at the day of the competition."

One thing I do differently with competitors is the pre-contest prep. Specifically the last two weeks, where I think most coaches make things more difficult and painful than what's necessary or optimal.

Andreaz is competing on Saturday, and is going up against guys a lot heavier than him (they cancelled his weight class). Let's hope they judge symmetry and conditioning fairly. That is where he really shines. I've helped Andreaz once before, where he took second place in his class (-70 kg) at the Sweden GP. He would no doubt have taken first, if it weren't for a Dutch (!) wildcard that appeared in the last second.

Here's a sneak peek on his current condition, one week out.

I should also mention that Andreaz is completely natural - and please believe that I wouldn't be telling you that if he wasn't.

Let's all wish Andreaz good luck on Saturday. You can follow his progress on his blog.

By the way, "Making High Frequency Training Work: Part Two" will be up on Monday, at the earliest. That will allow me to evaluate some relevant progress reports/client data being sent to me this weekend.

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

Welcome to the Internet's leading resource on intermittent fasting and all things related.

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