Yes, Virginia, a Calorie is Just a Calorie – Part I

That’s because a calorie is simply a defined unit of measure: a measure of heat. So, just as all meters, ounces, and hectares are fully fungible amongst members of their class with each being indistinguishable from another, so it is with calories. More specifically, when referring to calories in the context of food, every calorie in the world represents the amount of energy required to warm one gram of air-free water from 14.5 °C to 15.5 °C at standard atmospheric pressure.  If that were all there was to the story, then we could move on, but unfortunately, our work is not done yet because there exists an entire school of thought out there that extrapolates from this equivalence and pushes the thermo-chemical calorie into territory where it was never meant to go.   When people say that “a calorie is just a calorie”, they aren’t alluding to the above definition. Rather, what they mean is that the macronutrient source of a given calorie is irrelevant. Whether you derive 2000 kCal of energy from fats, protein, carbohydrates, or some admixture of the three, from the point of view of your metabolism, all possible combinations will be fully equivalent, assuming you maintain the same overall net caloric intake. This common understanding is far more interesting, principally because unlike the thermochemical definition in which the equivalence is tautologically true, the common view of caloric effects on metabolism is controversial, and that has made several authors quite a tidy sum as they argue for or against the premise.  Those arguing for full caloric equivalence go about it in a manner something like this:   chocotaco369 on Marks Daily Apple Let’s take two drinks: a 32oz coffee with 400 calories worth of sugar in it and a 32oz coffee with 400 calories worth of emulsified coconut oil. Both are consumed while said office worker is sitting on their butt in addition to all the normal calories they eat throughout a day. Which is worse?   While fairly typical of the breed, as far as arguments go, this isn’t much of one.  I expect that you have seen some variant of this sort of assertion and the very fact that it is repeated so often and from so many varied sources lends it the air of credibility.  As a proof technique, this is known as proof by repeated assertion – just hammer the point until resistance collapses.  It is also helpful if you can have multiple, hopefully seemingly unrelated, sources do the same hammering of the point.  Rote learning works like this.  You wind up “knowing” things without giving a thought to the derivation or underlying logic supporting those things, which is precisely the problem :  by virtue of the frequency of repetition of such arguments espousing the equivalence of calories, most of us have become inured to the glaring and unwarranted leaps in logic contained at their core.   It is quite remarkable that the exemplar we have above consists of only three sentences and by my count contains no less than eight fallacies!  That is an impressive error density, even the biblical apocalypse makes do with a mere four horsemen, and if this were the error density Olympics, I’d say we were looking at a gold medalist. Notwithstanding that, allow me to re-frame the assertions to explicitly reveal the contained error virtuosity: Restatement with explicit equivalence Let’s take two drinks: a 32oz coffee with an amount of sugar in it that would produce 400 kilocalories of heat when completely combusted in a bomb calorimeter and a 32oz coffee with an amount of coconut oil in it that would produce 400 kilocalories of heat when completely combusted in a bomb calorimeter. Both are consumed while said office worker is sitting on their butt in addition to all the normal calories they eat throughout a day. Which is worse?   With that done, I am hoping that the problem becomes readily apparent : you are not even remotely like a bomb calorimeter … which leads us nicely to the first fallacy.   Fallacy 1 : Heat of combustion is equivalent to biological energy metabolism   Some of you may have been wondering about that definition of a calorie given earlier, specifically wondering why it is given in terms of raising the temperature of water.  This is the end result of how the process of calorimetry is performed, and to help us understand that process, we can take a lesson from NASA.   On January 17, 1967, at 1:00 PM, EST, astronauts “Gus” Grissom, Edward White II, and Roger Chaffee entered the Apollo 1 command module for a launch simulation test...

The Heisendiet Effect

The Heisendiet Effect

The man in the photograph is Werner Heisenberg, a name that might be familiar to you in the guise of the eponymous Heisenberg Uncertainty Principle, or you might know it from the name of the antihero protagonist of Breaking Bad. The Heisenberg of Uncertainty Principle fame told us back in 1927 that when it comes to physical properties of a particle, there is a fundamental limit to what can be known simultaneously, so the more precise we are with respect to the momentum of a particle, for example, the less we can know about its position, and vice versa. The layman’s form of expressing this idea comes to us as a joke about Werner Heisenberg who is driving along the highway when he realizes that there is a police cruiser behind him, indicating that he should pull over.  He does, and the officer walks out of his cruiser and up to Heisenberg, asking him … “Sir, do you have any idea how fast you were going?”  To which Heisenberg replies, “No, but I know precisely where I am.”  This joke goes over really well in the lunch room at the Large Hadron Collider … The uncertainty principle is often confused with a related concept in physics known as the observer effect which states that certain systems cannot be measured without changing them.  If you think about it for a bit, this makes sense, and you probably run into the observer effect various times throughout your day.  For example, in order to measure the inflation pressure of the tires on your car, you first need to release some pressure into the pressure gauge.  But by doing so, you actually change the pressure in the tire, so your reading on the gauge is just an approximation of the actual tire pressure. Now you may think that releasing a tiny bit of air pressure from a tire in order to measure it is not such a big deal, and I would probably agree with you, but the observer effect manifests in other contexts as well, more specifically when dealing with observing people, and in that context, it is often known as the Hawthorne effect. Lessons from Western Electric   Over a period of several years, spanning from 1924 – 1932, workers at the Hawthorne plant of the Western Electric Company     in Chicago were the subjects of several experiments relating to productivity and how best to improve it.  Researchers experimented with altering various parameters at the plant to observe the resulting effect on worker productivity. One of the parameters to be altered was the ambient light.  Researchers reasoned that being better able to see what they were doing would improve worker productivity.  And, sure enough, when the ambient light was increased, productivity increased.  The effect, however, proved to be temporary and over time, productivity levels reverted to pre-intervention levels.  This was unexpected, but the researchers had several other interventions planned, so in order to test those and eliminate the confounding effects of their previous intervention, they returned lighting to its previous levels, intending to leave it there for a period to get workers reacclimatized to the previous baseline conditions.  Of course, they expected productivity to decline, or at least maintain … but the actual productivity improved. It turned out that irrespective of the actual intervention, increasing or decreasing ambient light, increasing pay, changing the temperature inside the plant up or down, all the interventions tended to increase productivity, but the increases were short lived, and quickly reverted to the pre-intervention mean.  Again, with perfect hindsight, this makes complete sense, people under observation behave differently from what they would normally do.  Once they become accustomed or inured to the observer, they revert to their true form.  Primatologists like Jane Goodall have made excellent use of this tendency of higher primates to study their true behavior by very slowly introducing themselves into a chimpanzee troop, for instance, and allowing them to habituate themselves to the presence of the researchers, at which point they revert to their true behavioral patterns. The Weak Form of the Heisendiet Effect   These principles also apply to those who undertake to change their diets, even if this is not being supervised by any researchers.  Even on self-monitoring diets, as for the Hawthorne workers, the mere fact that the diet is being observed will result in initial high compliance and adherence ( even over adherence ) to the diet protocol.  But over time, as one becomes accustomed to the intervention, one regresses to previous patterns and behaviours. This cycle plays out with alarming regularity every January 1, when untold millions undertake new dietary interventions, and...

Intermittent Fasting, Autophagy, and mTOR – Part I

Intermittent Fasting, Autophagy, and mTOR – Part I

Rob, a reader from Ireland, pointed me to a worrying post regarding the potentially negative aspects of intermittent fasting and asked about my opinon of it.  Ok, I’m being generous here by throwing in the modifier potentially, because the post’s author definitely holds the viewpoint that fasting will kill you … I’m paraphrasing here and exaggerating a bit for effect, but not much since the actual quote from the posts’s conclusion is:   John Kiefer The research consistently shows that the only thing IF brings to the table for athletes is detriment. IF shuts off the very anabolic processes on which we rely for improving performance. IF manages to drive beneficial metabolic processes into destructive cellular chaos. In the research, IF consistently demonstrates that is no better than an average for fat loss or muscle gain and it decreases athletic performance.   It has been said that extraordinary claims require extraordinary evidence, so, without further ado, let’s dive in to the “proof” of Kiefer’s pudding.   If you Can’t Dazzle Them With Brilliance, Baffle Them With Bullsh*t   Try as I might, I can’t follow Kiefer’s argument, mostly because I find it muddled and contradictory.  Things start off on the wrong foot when he asks the reader to suspend all disbelief and “imagine a purely destructive process that’s critical for building the very thing it destroys.”  Call me pedantic,  limited, or lacking in imagination, but to me a purely destructive process only destroys, it doesn’t build.  If it destroys and builds, then it’s not purely destructive, but rather, complex, subtle, and nuanced.   If you are in a charitable mood, you might be tempted to let Kiefer off the hook and chalk all of this up to enthusiastic overstatement – maybe he didn’t really mean that autophagy is purely catabolic.  Except that apparently, he really does mean it as he repeats this mantra throughout his post : “by definition and function, autophagy destroys tissue, making it purely catabolic.”  Not to nitpick, but even if we were to concede that autophagy is purely catabolic (it isn’t), autophagy does not destroy tissue.  Autophagy is active at the cellular level, while tissues are collections of cells.  This is a very important distinction for reasons that will become apparent later, I raise this issue here to point out that Kiefer might be a bit sloppy in either his understanding, or explanations, or both.   This stance on autophagy as purely catabolic is especially surprising when you realize that in his citations, Kiefer refers to a paper by Masiero et al. entitled “Autophagy is required to maintain muscle mass.”  I understand that Kiefer is a busy man as he is trying to build his nutritional conselling business, and he may not have had the time to read the full paper, or maybe even the abstract.  But I would hope that he at least had the time to read the title!  Trying to characterize something that plays a critical role in maintaining muscle mass as purely catabolic smacks of expending a lot of effort in pounding a square peg into a round hole.   But why is Kiefer doing this?  After all, he’s not dumb, far from it, as he tells us himself, “he’s smart as f*ck.”  Mostly, he’s trying really hard to create an association in your mind between autophagy and pure catabolism so that in the subsequent discussion, whenever you see the word autophagy, he would ideally like you to picture your body melting into a puddle of catabolic goo.  Because if he can sell you this purely catabolic disease, he can then sell you his cure, and it will only cost you $89.  The last thing Kiefer wants is for you to think of autophagy as complex, subtle, nuanced, and worst of all, tightly regulated:   Weidberg et al. (2011) Biogenesis and Cargo Selectivity of Autophagosomes More recent research has altered the original view of autophagy as a nonselective process by revealing the existence of molecules involved in selectivity of autophagosome cargos. …  Autophagy is tightly regulated to prevent its unbalanced activation, which may cause damage to cells. Studies have identified at least two signaling complexes that participate in the fine-tuning of autophagic activity under conditions of stress and other physiological circumstances in which autophagy is needed.   Selective autophagy includes a pathway for targeting specific hydrolase proteins ( the Cvt pathway ), one for processing protein aggregates (aggrephagy), another for processing ribosomes (ribophagy), yet another one for mitochondria (mitophagy), as well as pexophagy, a pathway for specifically targeting peroxisomes.  That is certainly a lot of pretty specific pathways.  As Shakespeare might have said, “if autophagy be the...

Intermittent Fasting – A Primer

This post has been a long time coming, and I’ve posted it in various forms, and bits and pieces in several internet haunts, but at long last, I’ve repatriated it here. When it comes to intermittent fasting, the amount of misunderstanding, misconceptions, and misinformation out there finally compelled me to put metaphorical pen to metaphorical paper here.   First thing first, just to get it out of the way, intermittent fasting is not a miracle cure for all that ails you. I think that there is a lot there to recommend it to people, I practice my version of it, and have been at it for coming on five years now, and I fully intend to keep doing it. I do recognize, however, that it cannot be all things to all people. If anyone tries to tell you that one size fits all, then you are dealing with a blatant charlatan and you ought to govern yourself accordingly.   What is intermittent fasting?   There is no clear cut definition, unfortunately, which contributes to the misunderstandings.  Wikipedia maintains that “Intermittent fasting (IF) is a pattern of eating that alternates between periods of fasting (usually meaning consumption of water only) and non-fasting.”  This definition is less than useless, as it practically suggests that eating the traditional three meals a day, and drinking water in between meals, which constitutes a pattern of eating alternating between fasting and non-fasting, is intermittent fasting.   For my part, I suggest that we adopt a pragmatic definition: “intermittent fasting is a pattern of eating that involves a greater interval between meals than generally culturally prevalent.”  So, if you habitually skip breakfast, you are fasting intermittently by our definition.  Skip breakfast and lunch?  Great, you fit the bill too.   One thing ought to be glaringly obvious in this definition due to its conspicuous absence: nobody said anything about calories. Should you choose eat breakfast, lunch, and dinner all at 7:32 PM EST every day, then you are intermittently fasting by this definition.  With that out of the way, we can dispell the first myth of IF – it is not starving.  Starving yourself does fit within the definition, but it is a degenarate case.  If you have some masochistic need to starve yourself and then call it IF, you certainly can, but the definition in no way requires it.   Why would you fast intermittently? The Intuitive Answer.   Going back to the intermittent fasting definition, at some point someone realized that to a large extent in modern society meals and meal times are culturally rather than biologically determined.  It didn’t always use to be that way, and we have the linguistic archeological record to prove it.  The word breakfast (as said by Sean Connery, the best of the Bonds in my opinion)  used to define a functional meal, the one that broke your fast, even if that were daily at 7:32 PM EST.  In modern society, the word has been co-opted and transformed from a functional definition into a cultural one where breakfast is your morning meal, generally consumed before heading off to work.  I expect that this arose as a consequence of industrialization given that factories thrive on predictability and conformity.  It is not clear to me that people thrive on conformity to the factory whistle, a point most eloquently made by Connery’s Bond who eats because he is hungry ( a biological imperative ), not because the time is appropriate for the meal ( a cultural imperative ).  The question is then, what is an eating frequency that is compatible with a biological imperative?   Another intuition that helps us answer the frequency question is the realization that there is a continuum of possible feeding schedules, and most of it represents ridiculous extremes.  Assuming we are aiming at a 3000 kCal diet, and sleep for 8 hours a day, we could eat 0.05 kCal for the 57600 seconds that we are awake.  That is, we could literally be constantly eating, albeit a miniscule amount of food each time.  This represents a practical upper bound on how frequently one could eat. For a practical lower bound, consider attempting to eat a week’s worth of food at one sitting, or 21000 kCal at one meal.  Assuming that our diet consisted of the most energy dense food we know, dietary fat, we would need to eat 2.33 kg, or 5.1 lbs, of fat at this meal.  Never mind the practical aspects of actually digesting this amount of fat, just the thought of attempting to do this is enough to revolt me.  So, it would seem that a reasonable continuum has once...

How Kim Lost 10 lbs. in 10 days!

How Kim Lost 10 lbs. in 10 days!

That’s what the breathless headline blared from the cover of the celebrity tabloid at the magazine stand.  Now, I’m not much for gossip, so I didn’t read the article.  As a result, I am completely in the dark when it comes to what dietary strategy, supplements, exercise, or other tactics Kim employed to achieve this newsworthy outcome.  I do know a few things about metabolism, however, and this gave me pause. The implication of the headline is that the weight lost was fat, so naturally, we may ask what would one have to do in order to lose one pound of fat per day?  By now, it is more or less generally accepted that one pound of fat is 3500 calories, so Kim would have had to create a daily caloric deficit in that amount.  And how does one go about creating a caloric deficit?  Well, everything boils down to a variation on two themes : eat less calories, or burn more of the calories that you are taking in. Since I’m not really sure what Kim was eating, we’ll explore a couple of options with respect to her diet.  We’re also going to need to be able to come to grips with Kim’s calorie burning activities.  In order to estimate what kind of activity Kim had to engage in while trying to achieve her weightloss target,  we’re going to use Metabolic Equivalent Units, or METs where one MET is equal to 1 calorie burned per kilogram per hour at rest ( 1 cal kg-1 h-1).  Different activities have different METs levels, and they scale linearly, meaning that if you engage in a 10 MET activity, you are actually burning 10 calories per kilogram per hour, for a 13 METs activity, you will burn 13 calories per kilogram per hour and so on. Kim is 5’3″ and weighs in the vicinty of 130 lbs. or 60 kilos ( I assume ).  Our interest in Kim’s weight goes beyond salacious gossip, we only care about her overall mass because we want to compute her basal metabolic rate.  As a bare minimum, assuming Kim is a creature of pure leisure and spends an entire day at rest ( 1 MET ) Kim burns 1 cal kg-1 h-1 x 60 kg x 24 h, or 1440 cal, well short of the 3500 calories she needed to dispose of daily in order to achieve her weight loss. But of course, Kim hardly stays at rest the entire day.  She presumably has other matters to attend to, so, we need to make some more assumptions about how Kim spends her day.  Accordingly, assume that Kim sleeps for 8 hours, works for 8 hours, engages in leisure activities for 3 hours, household activities for 3 hours, and dilligently exercises for the remaining 2 hours.  Armed with this, let’s consider two incarnations of Kim, Extreme Kim and Reasonable Kim.   Extreme Kim (EK) Extreme Kim is goal oriented, analytical and very focused.  She knows exactly what she wants and how to get it.  She is a career woman whose work day is filled with meetings and intense bouts of “getting things done!”  Since she set her mind on losing that excess weight, EK has decided to forgo eating entirely for the duration.  There is no better way to create a caloric deficit than by not eating! Since EK sleeps for 8 hours a day, she consumes 1 MET per hour, per kilogram, or 1 cal kg-1h-1 x 8h x 60 kg , which is 480 calories.  Now, the government has gone to the trouble of computing METs values for all the categories from the American Time Use Survey and from scanning through the “Working and Work Related” activities, it looks like those not involving heavy physical work ( i.e. management, business and financial, legal, computer and technological ) seem to range in METs from between 1.5 and 2.5 ( see the table below ).  We’ll split the difference and say that Kim expends 2 METs for every hour that she’s working, which makes her work caloric expenditure double that of her sleeping rate, or 960 calories! Not bad, but we’re 2/3 of the way through the day, and we’ve only gone through 1440 calories, or about 2/5 of what we need to do. For her household activities, let’s say that EK engages in rather vigorous ones, which boost her METs to 3.5! This gives her an additional calorie burn of 630, bringing the total to 2070.  In terms of socializing and leisure activities, that’s about 2 METs for 3 hours, or 360 calories more.  The running total is now at 2430 calories, and EK...