Monday, August 31, 2009

Ghrelin and entrainment

"New" research on ghrelin

Apparently, scientists have now discovered ghrelin's role in meal initiation and it's entrainment to habitual meal patterns. Funny, because I've been talking about this since I started the blog. Judging from the quick look through my collection of ghrelin related research papers, it seems the earliest paper mentioning this effect of ghrelin in humans is from 2001. The entrainment of ghrelin is part of what makes the 16 hour fast so easy after a few days adaptation.

Though it's not mentioned in the link, ghrelin has other interesting effects as well, such as stimulating brain functions of spatial learning and memory development. From an evolutionary perspective this makes sense; the urge to find food may create more competitive skills to ensure survival.

In a similar vein, the metabolic increase (via incrased norepinephrine/epinephrine) that occurs during short term fasting is a function of the body telling you to not sit on your ass, but go out and find food - another mechanism selected for during evolution. Yes, you read that right, "starvation mode" is a bunch of hokum, unless we're talking long term fasting (>72 hrs).

Either way, the link might be worth a read if you're not familiar with ghrelin. Will at least provide you with some backup material when people ask you why you aren't starving during the fast.

And when someone asks you why they're constantly hungry on their six meal-a-day-foo-foo-meal-regimen, you can refer them to dr Silver -

"If you eat all the time, ghrelin secretion will not be well controlled,” said Silver, the paper’s lead author and the principal investigator of the study."

Saturday, August 22, 2009


* Some time ago, Super Human Radio featured Dr Mark McCarty, co-author of a study on fasting and exercise.

Exercise After Mini-Fast Burns Fat And Builds Muscle

Some good discussion here if you can stand the commercial breaks.

What I found impressive was the high adherance rate, as well as the effectiveness of the approach, compared to the usual standard seen in weight loss interventions - especially considering that participants were allowed to eat as much as they wanted throughout the study (though low fat, low glycemic food choices were encouraged).

Here's a few excerpts from the full text version of the study -

"With respect to the long-term sustainability of this regimen, it may be noted that author M.F.M. has followed this regimen for 12 years and, at age 56, maintains a body fat under 5%, having lost approximately two-thirds of his initial body fat."

Damn, sounds like Dr McCarty is ripped.

"It stands to reason that, if daily exercise is conducted in a way that optimizes oxidation of stored fat, and if subsequent meals are low in fat so that this oxidized fat is not immediately replaced (but a satisfying repletion of glycogen stores is achieved), a daily negative fat balance can be achieved that will persist until a new equilibrium is reached at a much lower body fat content [1,2,7]."

This goes in line with some of my own thinking regarding the post-workout overfeedings.

"Clinically, meal skipping has been associated withreduced risk for colorectal cancer in several epidemiological studies [24–27], and serum lipid profiles and plasma levels of acutephase reactants tend to improve during the month of Ramadan
in observant Moslems [28–31]."

Good stuff.

Bahadori B, McCarty MF, Barroso-Aranda J, Gustin JC, Contreras F. A "mini-fast with exercise" protocol for fat loss. Med Hypotheses. 2009 Jul 2. PMID: 19577377.

Read the abstract here

* Andreaz Engstrom, competing bodybuilder and former client of mine, put together a video showcasing some of his progress made with intermittent fasting this summer.

I coached Andreaz for a competition back in April. Shortly after competing, Andreaz got sick with shingles, which prevented him from training for six weeks. As you can see, he made a swift comeback. You can see his before/afters leading up to the competition in this post.

* Alan Aragon on supplement marketing . Good article, but I suspect he may be preaching to the choir. Nonetheless, well worth reading.

Wednesday, August 19, 2009

Another Interview

Here's a recent interview I did for a dutch site.

Other interviews and articles can be found here.


Martin, we can all read your bio on your blog, but what have you been up to in the last 6 months? Any news on a book for example?

I've been keeping very busy with clients, articles (for the swedish bodybuilding mag "Body") and book writing. More of the former, less of the latter, but I'm picking up the pace to get the book out fairly soon. I actually have a date set in my mind, but won't say anything more on that topic. It'll be done when it's done (and hopefully worth the wait).

Some people complain of headaches during the fast, any idea what causes this and better yet, how to solve it?

The most probable cause in this context is hypoglycemia and the headaches are likely to occur after low carb (rest) days. I rarely encounter this among my own clients, but I'd wager a bet that most people experiencing the headaches are eating very low carb/ketogenic on rest days, which is why hypoglycemia may occur early in the fast on the next day. If that is the case, I'd then suggest to up carb intake on rest days - 1 g cho/kg body weight is a good starting point. The goal is not to hit ketosis on rest days like some people seem to believe; if you do, then you're doing it wrong (and shifting in and out of ketosis isn't exactly ideal for mental performance either). Make sure protein and carbs are high enough to not go ketogenic on rest days if you're having problems with fasting headaches.

Another factor that plays into this is the caloric surplus and deficit; if you're having headaches, make sure that the gap between training days and rest days isn't too steep in terms of calorie surplus/deficit. Large swings, i.e eating +50%--50% maintenance/ on training/rest, can also cause headaches and other mood disturbances during the fast.

Other possibilities not related to hypoglycemia include dehydration and caffeine withdrawal, both easily solved by drinking more and keeping your regular caffeine habits intact.

If all of the above can be ruled out as explanations to your headaches, studies show that there is a pretty strong genetic predisposition to migraines, which can be triggered by very small fluctuations in blood glucose - if that's the case, well, fasting simply isn't for you, and you may in fact be better off with more regular meals.

Do you recommend a different training approuch especially volume wise when following the IF guidelines?

Whatever works for you will work just as well on an IF regimen. That being said, I am biased towards a certain style of training; my own training methodology is inspired by the works of Stuart McRoberts and Arthur Jones, for example, and puts a heavy focus on training core movements with proper intensity and set structure. I also consider some of the 3-5 x 5-templates out there to be solid, success-proof, routines. So sure, given that I believe 90% of trainees out there are much better following the likes of these training routines than the stuff I see people doing in the gym, these are approaches I would recommend for most people doing IF as well; but again, there is no need for a special approach due the diet. However, for fasted state training, i.e if you're working out at the end of the fast (with only a small amount of BCAA, as I recommend as a pre-wo 'meal'), I would definitely recommend starting out doing shorter weight training sessions as a general rule for everyone.

A lot of questions are asked about recomp. Lots of powerbuilders (not bodybuilders) want to get leaner, but don't want to loose a lot of bw and especially no strength! Can you give us some guidelines about recomping (eg some people say +25% kcal on training days and -50% kcal on off days)?

That's what most people want, and it's not something easily covered in a few lines here. On the topic of the diet, I'll say this: if the +25%/-50%-approach is working for you, that's great. If it isn't, consider keeping a tighter caloric interval, especially if you're already lean. And what is absolutely crucial - make sure to get a lot of protein on rest days.

Is bulking up just a matter of upping the calories or do you have some special approuch for this as well?

Another topic that I won't try to cover in depth here, rest assured that special measures have to be taken if you want your gains to be lean. First of all, training wise, I do things differently. Aside from visual cues, I rate the quality of gain by relative strength. If anything, that is something people should take away from this interview. Look at your weight gain in relation to your strength gains. If you're losing reps in chins on your bulk, odds are you're getting fat. If you've gained 10 lbs on your bench in the last month, while similarily gaining 10 lbs of body weight, you're getting fat. You get the point. I have a system for that, sort of a minimum standard of relative strength I think people should gain in relationship to their weight. This is complex and dependent on training experience, body leverages and so forth. Needless to say, there are exceptions such as training a beginner or when introducing a new movement, the system cannot be applied.

Diet wise, it's a matter of finding the sweet spot when it comes to weight gain, calorie intake and macros; dependent on training experience and insulin sensitivty, among other things.

What do you think are average natural muscle gains in a month's time?

Hard to say, since there is such a tremendous variability here. However, assuming that a) you've already tapped into your newbie gains, b) you're not completely retarded when it comes to your diet or training regimen and c) you wan't to keep the gains lean, then we're looking at 1-1.5 lbs per month for most people.

Anything else you don't want my dutch readers to miss out on?

Nothing I can think of.

Sunday, August 16, 2009

Questions & Answers

Another Q&A. Click here to see all Q&A's.

Intermittent Fasting and Testosterone

First a question related to the effects of dieting on testosterone and libido/reproductive function in general -

Q: "My sex drive just winds down to nearly nothing when I'm running an intense caloric deficit. Is there some documented/anecdotal correlation on this, or is it random according to the individual?"

A: It's not random, it's a fact that weight loss/calorie restriction, even moderate in nature, causes a delayed response to gonadotropin-releasing hormone (GnRH). This neurohormone is secreted in a pulsatile manner from the hypothalamus, and upon binding to receptors in the pituitary gland, it activates synthesis of reproductive hormones, luteinizing hormone (LH) and follicle-stimulating hormone(FSH). This axis is partially under control by "master" hormones involved in sensing the general energy status of the body; leptin and insulin, for example.

An energy deficit lowers leptin, which in turn impacts the reproductive axis negatively. This makes complete evolutionary sense, when you consider that reproduction is such an energy costly process. Conversely, high body fat percentage also affects the reproductive axis negatively, through other mechanisms -insulin resistance being one major cause discussed in this context.

Looking at studies on this topic, the effect is proportional to the energy deficit. In one paper, they noted that the delayed response in GnRH pulsatility was "intermediate in extent" when comparing moderate weight loss (-1% body weight/week or some such) to that of anorectics or VLCD (400-800 kcal/day).

My personal experience is that a moderate deficit (i.e net deficit/week is moderate, say -3500 kcal) has no noticeable impact, while a high deficit (i.e -7000 kcal/week) has a negative impact. The latter is augmented on very low carb or straight ketogenic diets. Cyclical diets are superior in this regard.

And related to intermittent fasting -

Q: "I also have a question for you, regarding IF and testosterone. I found a study(done in rats,yeah) , which states that the IF mice had a much higher Testosterone to Estrogen ratio; one of the comments of the study "makers" was that in response to absence of food, males increase their testosterone in order to reproduce quickly as possible. Ok , it's very nice , but does this apply on humans? I mean are there any studies which concluded that IF raises testosterone in human males?"

A: Humans and rodents are not alike when it comes to the effects of fasting on the reproductive axis. For example, you'll see similar responses in female rodents becoming "hypermasculinized" when put on a 40% calorie restricted diet, which is obviously not the case with humans.

There's not a whole lot of studies that can be rightfully applied to the intermittent fasting protocol I am advocating, with 16 hrs of fasting and 8 hrs of feeding. The ones that come closest would be the Ramadan studies, which show a shift of the peak and nadir, but no reduction of the mean. Bascially, testosterone reaches it's peaks and low points at different times compared to a regular feeding schedule, but there is no impact on the average levels. Testosterone in blood plasma divided by 24 (hours) on Ramadan equals baseline (pre-study) levels.

Most studies in this context are carried out using prolonged fasting (48-72 hrs) and show a significant decline at the 36-48 hr mark. For example, one study fasted men for 56 hours, compared blood tests of the last 24 hrs and found lower levels compared to baseline. Other studies using similar setups found the same results (of note is that age plays a factor, and men 50 yrs+ seemed immune to these effects). Additionally, leptin replacement during prolonged fasting restores LH pulsatility and testosterone levels, which goes to show that plummeting leptin levels during prolonged fasting is responsible for the negative effect.

In summary, there is no evidence that short term fasting, which is what I recommend, impacts negatively on testosterone. Prolonged fasting has a negative impact, and this is related to the acute energy deficit and concomitant drop in leptin.

Here I go off on a tangent or two -

Speculatively, I suspect that the intermittent fasting protocol a la Leangains might alter the rhythm of testosterone and LH pulsatility in a similar manner as Ramadan, meaning your peaks would be different from that of the habitual breakfast eater. Ghrelin, which is also a key player in the reproductive axis, adapts to your habitual eating pattern and is altered compared to a more regular feeding schedule. High levels (such as in anticipation of a meal) inhibit GnRH secretion while low levels (such as after meals) stimulate it. Simply put, you may get hornier later in the day, although I've heard many anecdotal reports suggesting the opposite. Needless to say, there are many other, environmental factors that come into play here.

Also, recall that I always put the overfeeding phase post-workout. This will put your body in an acute positive energy balance and increase leptin; downstream effects of leptin will impact positvely on GnRH and testosterone, and provide a favorable hormonal environment for protein synthesis and anabolism. These effects would be especially welcome during a diet and perhaps one reason why intermittent fasting, according to my experiences, have shown such a remarkable effect on muscle and strength preservation during dieting. Admittingly, there are too many confounders here for me to make any definitive statements on the matter (is it the training, the diet etc).

Will aspartame kill me?

Q: "I was just wondering what your thoughts were on the use of artificial sweeteners (aspartame in particular). I love using them but have heard mixed advice regarding their safety. Some "experts" say they're fine in moderation, others say they can cause brain tumors and should be avoided like the plague. As in my eyes, you seem to be the one true "expert" on diet/training, your opinion would be greatly appreciated. Many thanks"

A: Aspartame was found to cause brain cancer in rodents, but no human trial has ever shown a link to cancer, or any other serious disease, for that matter. This has been examined extensively; for example, see this study with almost half a million subjects -

And here's another one -

I could go on, but the consenus is that aspartame is very safe for human consumption, and I have nothing against it.

Also, I should note that the rodent studies used such extreme dosages that it would be impossible for any human to ingest that amount save from walking around with an IV-drip of pure aspartame 24/7.

Transferring from dieting to maintenance

Q: This client had been dieting for several months and lost close to 25 lbs. It was time for transfering him to a maintenance protocol, which meant increased calorie intake. This is some of the advice I gave him.

A: As for your diet, I really recommend sticking to the same foods, or at least the same food types (lots of veggies, lean protein, no shakes etc) but in greater quantities for the first few weeks coming off the diet - trust me on this. Don't try adding in too much of anything funny like cheesecake or icecream or even cereal in your pwo meal. You WILL have a more lax attitude after this diet, and if you combine that with some really tempting foods, you'll risk a binge sooner or later. And that's a sure fire way to pack on the fat again after this long diet stint. You'll see I've changed the meal plans as well, simply added more of the old foods. Not that you need to use them either, but it's just to give you an idea.

He wrote back: "...make sense and I appreciate your advice to not deviate greatly from the food choices I made during the diet phase. It's good I enjoy those foods, so keeping them in my diet isn't an issue. With the added carbs, I'm going to take advantage and add more fruits and vegetables into my diet."

Furthering my point, I replied: Yes, that's perfect. More veggies and fruit. Changing food sources for novelty after a diet is one of the prime mistakes people make (but you don't hear people discussing this very much). It's a psych phenomenon, as deviating from their typical foods will put the majority in a more lax/liberal state of mind, esp after long bouts of dieting, which greatly increases the risk of going 'fuck this, this was so good that I'm gonna stop counting for today and just have a little bit more' and they then end up eating boxes of cereal and other high carb dense foods in the pwo meal.

Intermittent fasting and genotype

these questions comes up from time to time -

Q: "...would IF work for an endomorph?"

"Is there a particular genotype that seems especially suited to an IF eating pattern?"

A: The notion of people being born with a certain body type, somatotyping, has been around for ages. Though oversimplified, the idea holds some truth in that levels of hormones and neurochemistry are largely determined by genetics and gives a propensity for fatness, leanness and muscularity. The endomorph is basically a person that puts on body fat easily, also called the "thrifty" genotype, and the ectomorph, "spendthrift" genotype, is the person that seems to stay naturally thin and has a hard time gaining weight. Mesomorphs are muscular.

Part of the reason for endo/ectomorphism can be explained by the response to calorie intake. In short, ectomorphs match calorie expenditure to intake very well, and spontaneously; when overfed, they increase activity levels spontaneously (fidgeting, can't sit still etc) to burn off the excess calories, while this response is not seen in endomorphs. Overfeeding is also accompanied by an increase in resting energy expenditure in ectomorphs, while the effect is blunted in endomorphs. These are factors we cannot affect by dietary manipulation.

However, this is the interesting part.

Brain imaging reveals defects in the reward system of endomorphs, in that they have a poor concentration of dopamine (D2) receptors in an area of the brain that controls food intake. Dopamine is releases in response to pleasurable activities, such as eating, and is partly responsible for getting that satisifed feeling after a meal. If receptor density is low, more calories need to be ingested in order to reach that threshold - and endomorphs are screwed in this regard, in that they need larger meals than others to receive the same effect. The D2 dysfunction is one of the key genetical factors in causing obesity, and various D2 agonists are currently being proposed as possible drugs of choice to "cure" the obesity epidemic. Additionaly, D2 receptor dysfunction also predisposes individuals for various other addictive behaviors linked to the reward system (drugs, gambling, sex etc).

But let me get to the point. If there is a certain threshold of dopamine to be reached before feeling satisfied, and seeing that this response is blunted in endomorphs due to low receptor density, an intermittent feeding pattern would make a lot of sense for the endomorph trying to lose fat. Fewer and bigger meals would achieve the effect, while small meals throughout the day would just be half-assing it and never really deriving any pleasure from the food. The meals would be rewarding, and this brings me to the second argument for an IF meal pattern for endomorphs, which is the anticipation of reward.

Anticipation of reward has a very potent effect on dopamine levels. Think of how happy you were just hours before waiting to see an eagerly anticipated movie or going to an event you had planned for ages, only to find out that the movie/event itself was relatively disappointing (vs expectations). Parties, sex, food, gambling. Great excitement beforehand, yet often out of proportion to the feelings derived from the event itself.

Relating to the context discussed, the mere anticipation of the first meal after the fast, which is large and satisfying, may via increased dopamine have a suppressive effect on appetite. It may also improve other behaviors related to dopamine, such as sense of well being and motivation for work and achievement.

Therefore, endomorphs, and people with low basal dopamine levels (in psych referred to as "novely seeking" aka all-or-nothing personality types), may find themselves particularily suited to an intermittent fasting pattern. I should note that I am a legitimate novely seeker myself, as confirmed by rather extensive tests (long form Temperament and Character Inventory, for those in the know). Anecdotal reports from succesful clients also seem to suggest they may be of this temperament.

That being said, the above is a mere hypothesis at this point, and I am not really doing it justice by presenting it in a few lines in a Q&A post like this. More elaborate and referenced writings on this will likely appear in the book.

Extreme dieting, yet no fat loss?

Q: Recently, I got contacted by an old client of mine. He got very lean after his diet, but attending a few festivals during the summer got him out of his normal rut, and upon returning home he binged on junk foods for a few days. Eager to get back to his former leanness, he embarked on an extremely restrictive diet combined with copious amounts of cardio. Despite this rigorous regimen, appearance or scale weight didn't change much at all. He sought out my guidance again, and here are some excerpts from the conversation.

A: Yes, this is hardly surprising. You should have known better, but the correlation between prior dieting experience and rational behavior at times seem surprisingly weak. Even the best tend to do stupid shit from time to time.* As I've told you before, one of my friends is a coach himself, yet always hires another coach when he embarks on a pre-contest diet. Why? Most people tend to lose their objectivity and do stupid shit when left to their own devices. I used to do stuff I never would have advised anyone else to do, and it took several years before I finally learned.

It's the dumbbass diet you decided to put yourself on that causes the water retention. Extremely low calorie intake and HIIT cardio is a fantastic recipe for chronically elevated cortisol levels, which in turn causes water retention. If you've seen someone undergoing hydrocortisone treatment you'll know what I mean. The diet you're on now isn't much different, except the effects are more systemic rather than localized to certain tissues.

And then I told him my secret solution, which was basically to cut cardio substantially, along with a slight increase in calories, namely carbs pre- and post-workout.

The take away point here is this. Scenarios like the above, seems to happen a lot - people get lean, they binge, get some temporary bloatedness and they compensate by doing stupid shit against their better judgement. This will just aggravate the problem Fix your head and look at what the hell you are doing. A 1200 kcal/day no carb-no fat diet might sound like a good solution when your head is all messed up and you want to get rid of the bloat, but just wait it out and you'll see that it isn't as bad as you thought.

I should mention that cardio is the real killer here, not low calories per se. High frequency HIIT causes water retention due to cortisol. Long duration cardio, such as jogging for an hour or more daily, will cause it by an adaptive mechanism called hyperhydration. Competitive long distance runners and triathletes are keenly familiar with this, as they will sometimes lose weight after an event rather than when preparing for it.

Low calorie intake by itself is fine, but bad stuff happens when you add lots of cardio to the equation. And besides water retention, there's the more obvious drawbacks such as lethargy and general feelings of shittiness to cope with.

* In Fooled by Randomness, highly recommended, the author notes that researchers are overrepresented in failing to learn from past mistakes. In the same vein, I've noticed that theoretical knowledge about nutrition and training rarely show a strong correlation to good results among health and fitness minded people.

Sunday, August 9, 2009


I'll have another Q&A up soon, but I figure I'd drop by real quick and link some worthwhile reading and listening material.

* Ryan Zielonka writes about his experience with my RPT system.

"Intelligent HIT – the kind promulgated by Martin, at least – keeps volume to a minimum. Major movements are trained infrequently. Martin has taken his cues from guys like Arthur Jones and Stuart McRobert, altering the workout week to an extended 8-day schedule and emphasizing progressive overload over volume."

..."For the past four weeks I was in the gym three times every eight days. My bench press improved by 30lbs for five reps. My deadlift improved dramatically, over 80lbs for four reps. Back squat didn’t move as much as I would have liked, from four to six reps with a 15lb increase in weight."

- Ryan

Some pretty solid gains. I've been getting e-mails from people that tried my template from The Minimalist, reporting similar increases - the most notable being +160 lbs deads, +120 lbs squats and +75 lbs bench over 100 days (10 x 10-day cycles).

* In the trenches with Alan Aragon. Alan talks some sense on various issues. There's a brief discussion related to intermittent fasting.

* The Energy Balance Equation

For example, people will point out that replacing carbs with protein leads to greater weight loss although they have the same calories; ergo the equation is wrong. What they fail to realize is that protein has a higher thermogenic effect and this modifies the TEF value of the equation; the energy OUT side of the equation changes if you replace carbs with protein.

- Lyle

Let me talk about that last part for a minute. A new study recently came out where it was shown that increasing protein from 12% to 30% lead to an approximate increase of 75 kcal/day at the same total calorie intake (1). A researcher named Livesey proposed that the impact of 1 gram protein on your metabolism is about 3,25 kcal, and not 4 kcal (2).

Back in 2004, I came across Livesey's findings and created a diet called The Thermogenic Diet (4) - basically, a very high protein, moderate fat, low carb TKD (3). It's not very different from PSMF, but more liberal when it comes intake. I released it as an article on one of the swedish forums, where it became an instant hit, and still is. Among the many people that have used it with great success is natural bodybuilder and client of mine Andreaz Engström

Keep protein high, and you will lose fat at a higher calorie intake than on any other macronutrient combination. What's the point of this rambling? Not much, except serving as a reminder for you to eat your protein when dieting. A lot. Keeping protein high is a given; carb and fat intake is much more dependent on your personal preferences, and should be treated accordingly.

1. Veldhorst, et al. Gluconeogenesis and energy expenditure after a high-protein, carbohydrate-free diet. Am J Clin Nutr. 2009 Jul 29.

2. Livesey. Metabolizable energy of macronutrients. Am J Clin Nutr. 1995 Nov;62(5 Suppl):1135S-1142S. See this post for more ("Q: Why is protein kept so high on rest days?")

3. TKD - Targeted Ketogenic Diet (except with the Thermogenic Diet you'd not hit ketosis due to protein being so high)

4. There is no english translation available, but maybe I'll look into that if enough people are interested in reading it.

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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