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If this is at all interesting to you, I highly recommend Gary Taubes' Why We Get Fat and What to Do About it (http://www.amazon.com/Why-We-Get-Fat-About/dp/0307272702)

which is a more accessible version of his more rigorous book Good Calories, Bad calories.

I've been on a bit of a health binge since the beginning of the year and have been doing lots of research into these things. In a nutshell, not all calories are the same the some can wreak havoc on your system (grains, it turns out, aren't that good for us). The Paleo Solution, by Robb Wolf, is another great book - he goes to great lengths to discuss the science and biochemistry behind the points he is making. Highly recommend.



I've read GCBC and initially found it quite persuasive. But it seems that Taubes isn't really correct. The best refutation I've seen is from obesity researcher Stephan Guyenet.

From http://wholehealthsource.blogspot.com/2011/08/carbohydrate-h...

I hope you can see by now that the carbohydrate hypothesis of obesity is not only incorrect on a number of levels, but it may even be backward.  The reason why obesity and metabolism researchers tend not to take this idea seriously is that it is contradicted by a large body of evidence from multiple fields.  I understand that people like ideas that "challenge conventional wisdom", but the fact is that obesity is a complex state and it will not be shoehorned into simplistic hypotheses.

Carbohydrate consumption per se is not behind the obesity epidemic.  However, once overweight or obesity is established, carbohydrate restriction can aid fat loss in some people.  The mechanism by which this occurs is not totally clear, but there is no evidence that insulin plays a causal role in this process.  Carbohydrate restriction spontaneously reduces calorie intake (as does fat restriction), suggesting the possibility that it alters body fat homeostasis, but this alteration likely occurs in the brain, not in the fat tissue itself.  The brain is the primary homeostatic regulator of fat mass, just as it homeostatically regulates blood pressure, breathing rate, and body temperature.  This has been suspected since the early brain lesion studies of the 1940s (47) and even before, and the discovery of leptin in 1994 cemented leptin's role as the main player in body fat homeostasis.  In some cases, the setpoint around which the body defends these variables can be changed (e.g., hypertension, fever, and obesity).  Research is ongoing to understand how this process works.


Many obesity researchers find Guyenet to be quite the joke.

For example, Peter over at HyperLipid recently ripped him to utter shreds:

http://high-fat-nutrition.blogspot.com/2012/06/confused.html

http://high-fat-nutrition.blogspot.com/2012/06/insulin-un-de...

Not to mention, Taubes countered Guyenet with a 6-part series refuting Guyenet's widely mocked food-reward/palatability hypothesis:

http://garytaubes.com/2011/09/catching-up-on-lost-time-ances...

The thing is, there's a lot of infighting; These guys are always going back and forth. They both have their camps. Those both have their arsenal of studies. It's almost a sport...

The simple fact of the matter is that we're not really going to actually know conclusively and incontrovertibly one way or the other for at least another decade.


I'd just like to say that my athletic performance, body composition and mental clarity have been far, far better on paleo than any other diet. I'd also recommend the two books gxs mentioned.

Of course, not all digestive systems are created equal and YMMV. For instance, wasn't until after eating paleo for a while I discovered I had a mild gluten and dairy intolerance (most people develop the latter).


Also, Zooko and Amber Wilcox-O'Hearn are reviewing the science related to ketosis and diet here:

http://www.ketotic.org/


Another book recommendation:-

Girth Control: The Science of Fat Loss & Muscle Gain - Alan Aragon

This is the bible, it has absolutely no fluff/filler content.


Taubes isn't taken seriously by most dieticians and nutrition researchers we talk to (I work at a nutrition startup).

I'd say that if there is any value to Taubes, it is this:

Different foods, given the same calories, will fill you up or nourish you at varying degrees.

300 calories of oreo cookies isn't the same as eating a banana and some chicken.

The main practical benefit people get from low carb, paleo, etc is that they're eating less sugar and junk, and thus eating healthy food with better overall satiety. As a result, they lose weight because they're eating fewer calories.

You can lose weight eating twinkies, it's just hard to do because it's bad for your health, not nutritious, and leaves you feeling hungry because it's all carbs.

A more scientific and less paleo-obsessed way to think about carbohydrates is this:

Carbs are fuel, if you're an athlete, you have a use for them. If you live a sedentary lifestyle, excess fuel isn't going to do you any favors.

Adjust accordingly.

In the end: calories in, calories out. Humanity hasn't defeated the laws of thermodynamics. It's just a question of how easy and healthy it is to maintain a sub-maintenance caloric intake.

Edit:

Okay people, I just got done saying low carb made sense if you weren't an athlete, what exactly are you arguing against? I agree with you guys, I just think the reasoning and rationale should be taken in the context of current nutrition research and not some demagogue's book that is obsessed with a dietary aesthetic rather than data.


The reason people are arguing against you is that even in 2012 on HN in the face of currently incompletely understood complexity people instantly start forming micro-religions complete with prophets and various 'higher-powers', and of course heretics and infidels.

I mean seriously this article pretty much says "wow, this stuff is complex and really hard to make sense of", and the top comment is "but I have found the truth in this book!"

I fully agree with you, I think the paleo approach has some pretty sound ideas. But when I hear people talk about how "evolution" commands we shall eat no grains I get really worried about how quickly educated people can turn science into magic.


>>but I have found the truth in this book!

Really? My comment pointed towards two books, and a follow up argument suggested Feinmans old well known article for kicks.

What exactly is the point you are trying to make? By contrast, your comment lacks any real substance other than accusing me inciting religious war and telling us about your burden having to worry that educated people turn science into magic.

Bullshit. Where are your articles? Please, point to the articles that show that a diet abundant in grain from carbohydrates is ok, let alone good for you.


You seem to be responding to claims the poster didn't make. Calm down and read the post again, without assuming an attack.


I am not sure how you can read accusation of religiously motivated blindness/idolatry as anything but an attack really, it isn't a well-reasoned argument against a position, just ad-hominem.

Coincidently I am currently reading the aforementioned book myself (oh no, I am a religous loon!!), and if anything I get the impression of an exacerbated person basically pointing out that:

1: The current status quo in nutritional science was established before there was large scale data to confirm/refute it. It was heavily influenced by very few (I believe he mentions 1 or 2) specific scientists and became orthodoxy almost through force of will not necessarily because the data (which they didn't have) actually supported the hypothesis.

2: There are now numerous studies and quite a bit of data that seem to at least point to alternative hypothesis that should be explored. I don't recall yet having seen the author claim even the carbohydrate hypothesis he talks about is correct, just that it should be getting more study/attention than it is in main-stream nutritional science, and that it is better supported by the study data we do have than the currently accepted hypothesis which the studies we undertaken to test.

3: The idea that sedentary lifestyles coupled with abundantly available food just doesn’t track with the actual data as obesity seems to track much more closely with availability highly refined carbohydrates and massively increased sugar consumption. That said both could well play into it, it isn’t necessarily an either-or but much like the famous global warming vs. number of pirates graph it also doesn’t show causation, just correlation, and perhaps meaningless/misleading correlation at that.

4: Explaining obesity by overeating is as useful as explaining alcoholism by overdrinking (okay, I just threw that in because it is a funny quote :))

His primary push that I have taken away thus far is ‘we should be exploring this hypothesis, which isn’t actually terribly new nor is it terribly radical’. He claims people generally aren’t for unclear reasons (though I haven't picked up any sort of conspiracy vibes yet, which I was expecting). I have looked around for someone to refute his book but all I found was a weak refutation in Reason[1] which he responded to, and in my opinion, destroyed the critique quite handily [2]. I would be very interested in any responses that actually take to task the quoted studies / science from his book instead of attacking him by-proxy by calling Atkins a kook.

[1] http://reason.com/archives/2003/03/01/big-fat-fake/print

[2] http://reason.com/archives/2003/03/01/an-exercise-in-vitriol...


1. You're misusing the term ad hominem:

>The mere presence of a personal attack does not indicate ad hominem: the attack must be used for the purpose of undermining the argument

(http://plover.net/~bonds/adhominem.html)

2. I'm not going to respond to (or even read) any of your points about nutrition because you seem to be arguing with someone else, not me! I have no horse in this race, because I've never looked into it. I think you and gxs rather misunderstood Homonculiheaded's words -- which were about the general way folk were arguing, and not really about specific points at all.


More importantly, there's a subset of diets which cater to the "I'm a lard-ass, how can I lose 200 pounds quick" crowd.

Other people are more worried about general health than getting their calorie consumption under 3000 a day.


I really, really appreciate your response.

The micro-religion fanatics were causing me to question why I even bother.


It sounds like you've probably got a lot of insight to offer the community here, but you're doing yourself and us a disservice to resort to name calling like that. Just let your knowledge speak for itself and let's all remain civil. At the end of the day we're all in a pretty tight knot community here. Or maybe I'm just a crazy hippy :)


You're right, but it's frustrating to have people dismiss an entire field of research out-of-hand just because they read a book. Or two.


>>Taubes isn't taken seriously by most dieticians and nutrition researchers we talk to (I work at a nutrition startup).

That's because most dietitians and nutrition researchers follow conventional wisdom, which was established back in the 50s and 60s. Taubes himself included an amazing commentary on how conventional wisdom is incredibly difficult to dislodge in medicine and related fields. He had no illusions about his book being enough to do it, especially since he's a science writer rather than a scientist.

But his work is very valuable, and his dissection of why we believe what we believe is spot on. He goes a little overboard in blaming carbs, but does an excellent job vindicating fats.


>>That's because most dietitians and nutrition researchers follow conventional wisdom

Sadly, you hit the nail on the head, 100%. That is exactly the problem, most dietitians will still try to sell you on the CDCs protein intake recommendation of 50g and and a diet that consists of 80% carbohydrates - which just plain contradicts mounting scientific evidence.

Furthermore, most people will just say you need a "balanced" diet, having taken absolutely no thought to consider why they consider certain diets balanced to begin with.

If you move past your comfort zone, to the point where you can draw your own conclusions, without needing to refer to government guidelines to validate your every belief, you will see that in a few years we will look back on our current recommended diets and laugh.

Taubes does a more than adequate job of trouncing the old thermodynamics, calories in, calories out argument. The guy does have a masters in Physics from Stanford, after all. I leave it to you to look it up.

Edit: Feinman on a calorie is a calorie and why it violates the second law of thermodynamics

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC506782/


"The guy does have a masters in Physics from Stanford"

???

I've got a Ph.D. in CS from UTAustin, but I don't think you would want to take medical advice from me.


The point was to show that Taubes has the education and training to critically review scientific literature. Not that he is an expert on medicine.


I disagree with Taubes reasoning for other reasons, but the point the poster made was that someone who studied physics at Stanford will understand how the Laws of Thermodynamics work.


>> Sadly, you hit the nail on the head, 100%. That is exactly the problem, most dietitians will still try to sell you on the CDCs protein intake recommendation of 50g and and a diet that consists of 80% carbohydrates - which just plain contradicts mounting scientific evidence.

In nutrition there is never ever (never ever) such a thing as a "scientific evidence".

All the nutrition research around is a pile of conflicting information. Just as an example, a short time ago in HN was pointed a research where "a calorie is a calorie" was proven, in the context of a diet.

I still remain convinced that having a basic clean nutrition and a decent amount and consistent of sport would turn any healthy individual (9x% of the population) into a fit one. People keeps feeling attracted to nutrition religions just because they think they can get in shape without changing their unhealthy habits.


Yes, the advice of all these old guard dietitians is working fantastically for us.


Looks around at all the diabetic, morbidly obese people.

Yep, working great.


How many of those people do you think follow the advice of a dietician even 25% of the time?


It's weird. Often times you'll hear people saying they ate an apple for desert instead of that chocolate souffle the waiter recommended, when their main meal was a 2000-calorie monster full of breaded chicken, onion rings and french fries. And then they will tell you their dietitian told them to eat more fruits, so they are following his/her advice!


First, it is my experience that most people do, religiously so, for a short amount of time (a month or so seems common). And then, the 20% for which this advice produces the expected result continues practicing it, and the 80% for which it doesn't work start following less and less religiously, until they don't at all.

That's mostly evidence that dieticians are solving the wrong problem. To borrow from another poster in this thread, if the composition of what you eat was enough to solve obesity, it is likely that saying "don't drink alcohol" would be enough to solve alcoholism. And yet, hundreds of years of experience show that it is wrong for the latter.

A diet that is easy to follow (such as Roberts' Shangri-La and Asprey's RFLP) is what dieticians should be striving for, but instead most of them recommend a regime that their clients are unlikely to follow (and then blame the clients).


I'm not sure I believe that most overweight people have even had the advice of a dietician.

I suppose things like the food pyramid sort of count, but even the old one didn't endorse the empty calories evident in shopping behaviors (i.e, chips and pop).


Sorry, I assumed you were in referring to people who have dietetic advice in general, but I now see you referred specifically to the morbidly obese.

> but even the old one didn't endorse the empty calories evident in shopping behaviors (i.e, chips and pop).

But it made the (now) classic "calorie is a calorie" mistake, so it implicitly okayed them.


Portion control is actually one of the primary issues, less so than the actual food being eaten.

Many people will eat relatively healthy, but due to poor satiety or portion control, still gain weight.


Lets roll in the science-mobile and discuss real, concrete things.

1. Not eating carbs has nothing to do with our hunter-gatherer origins, there are no over-arching truisms that can be made about the macronutrient distribution of how hunter-gatherers used to or currently eat. Concordantly, paleo "proper" insofar as it resembles utilizing our understanding of hunter-gatherer diets to eat healthier than a Standard American Diet is not necessarily low carb.

2. Eating carbs doesn't cause you to turn into the Stay-Puft man like magical fairy dust, even if they're relatively unhelpful to sedentary people as a nutritive calorie source. Sedentary people should get more protein and fat than carbs relative to what an athlete would.

Moving onto 'keto', which is the more GI/ketosis focused variety of low carb/paleo:

High-fiber and whole-grain calorie sources should be preferred to the opposite. The only thing that makes an apple not "junk food" is the fiber. Fiber has been shown to blunt the glycemic impact of carb-bearing foods. Apples are otherwise useless unless you really need the carbs to survive/fuel your activities.

>http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna...

>Determining which aspects of the Western lifestyle are truly aberrant for our species and pose the greatest risk of obesity is complicated by the conflicting and limited data on diet and metabolism in non-Western populations. For example, while Western diets are certainly more sugar-rich and energy-dense than more “traditional” diets and wild foods [4], [8], [9], many hunter-gatherers seasonally consume a large portion of their daily calories as honey [10], [11] (Fig. S2), which has high concentrations of glucose and fructose [12].

>As is typical among traditional-living Hadza, over 95% of their calories during this study came from wild foods, including tubers, berries, small- and large-game, baobab fruit, and honey [17] (Fig. S2).


>The only thing that makes an apple not "junk food" is the fiber.

This is an oft-repeated mantra among proponents of low-carb paleo-style diets, but it largely ignores the role of micronutrients and particularly phytochemicals in human health. An intelligent choice of fruits can provide a bevy of phytochemicals that lower the risk of a wide variety of ailments. Looking at the macros when talking about the role of fruit in diet is largely missing the point.


Also, hunter-gatherers may get a lot more calories gathering than hunting. Women often gather more food than male hunters, collecting things like tubers, fruits, honey, etc.

IIRC, Homo erectus evolved to eat a lot more carbs than homo habilis. It's only if you pick specific points in human evolution that you can say we didn't eat carbs.


Bit of a strawman, nobody takes the pritikin diet seriously either. The place and purpose of healthy fats is well understood.


It sounds like you haven't actually read Taubes' book. He makes the case that no fat is actually "unhealthy." Saturated fats, which have been demonized, are harmful if and only if they are consumed with a large amount of carbs. That happens to resemble the average American's diet, which is why saturated fat consumption is correlated with heart disease - but it does not cause it.


calories in, calories out

After a lifetime of fighting with my weight, including surgery to give me a fight change, I have to say that statement is the single most useless statement in a segment filled with misinformation. It is used by people who haven't struggled to (perhaps not intentionally) insult people who do. "Gee, can't you count. It's just a calorie."

The problem with that statement is it assumes our bodies are like a gasoline engine, where, yes, a calorie in is a calorie out. Our bodies are not like that. Instead, we take in many different kinds of fuels. Everybody's body is different in how it processes each of those kinds of fuels. More importantly, everybody's brain is different in how it reacts to inputs coming from the gas tank and engine.

Until you understand how the various fuels interact with your body, a calorie is a calorie is completely meaningless.

Carbs are fuel, if you're an athlete, you have a use for them.

Yes, yes, yes. I completely agree with this. The brain needs some carbohydrates to run. The body can, if absolutely necessary, convert other foods into carbs to make that happen.

The things paleo and the various low-carb diets do is give a structure around how to reduce those carbs, especially in a culture that worships the ultra-refined, processed-thrice, almost-straight-sugar carbohydrate.


My family has adopted a single rule. Never buy anything with sugar on the ingredients list. I am of course aware that a little fructose would probably not kill me not even long term, but the biggest problem in dieting IMO is keeping track of your inputs. This rule alone rules out enough crap to make us eat reasonably healthy as the correlation of added sugar to crap food is pretty high. So I understand why simple rules are important I just believe they don't have to be, never eat any carbs.


That's a great rule. I'm going to have to think about and talk with my family about how to implement that in a way that isn't me being a tyrant and them wanting to rebel (yay for the early teens :).

Oh, and I agree on the "don't have to be, never eat any carbs". I've posted elsewhere that I'm a literal food addict. I have to put a lot of structure in place or I go off the deep end. For me, I have best control when I say "no carbs, period", but that is my personal diet (err, that I try to stick to, anyway :). I think a more reasonable world might be "try very hard to avoid simple carbs".

If you aren't lucky enough to not have to care (whatever combination of genes and lifestyle causes that, I curse thee ;), then finding the combination that works for you is critical. I found it though a lot of experimentation (including a major experiment of re-working my body's plumbing because so many previous experiments had failed).


>The things paleo and the various low-carb diets do is give a structure around how to reduce those carbs, especially in a culture that worships the ultra-refined, processed-thrice, almost-straight-sugar carbohydrate.

So we replace one religion with another? The structure is good, but yeesh.


It's replacing a wholly-incorrect model with a potentially flawed, but partially-validated one. I don't think we have the body of knowledge right now to precisely model how a particular diet works vs. another, but we have observed that low-carb diets improve health and wellness.

This isn't to say we should all ditch our bread and pray at the Church of Paleo. But with our current state of knowledge, I think it's more intellectually dishonest to cling to provably false "scientific" models of how different diets affect the body, than to just go with something that works (but we don't really know why). The scientific method dictates that theories must be made to fit observation, not the other way around.

Consider this: a theory that the world was round prior to any evidence of such has no more validity than the flat-world hypothesis. Post hoc, you may find out that the Earth is in fact round, but the knowledge was gained from the observation, not the theory. So call it religion if you want, but it's actually more scientific than the alternative.


This particular "religion" is backed by studies that say it's the most effective way to eat to lose weight. Granted, the only studies I know about are the ones Taubes cites, but is there evidence to the contrary?

It seems to work for a lot of people and the science behind it makes sense to me. I don't see why it should be discouraged.


What part of the laws of thermodynamics imply calories in -> calories out? This belies a total ignorance of their actual meaning. The first law of thermodynamics would be satisfied in any of the following scenarios:

1. Your stomach explodes, releasing the caloric content of the food as heat over a brief duration

2. Your digestive tract decides to stop digesting, and passes the food through unmodified

3. Normal digestion

As you can see, conservation of energy is completely meaningless in the context of diet.

The second law of thermodynamics concerns itself with efficiency of processes. To apply it usefully, we'd take into consideration the different metabolic pathways of proteins, carbohydrates, and fats. We know for a fact that the pathway for sugars is thermodynamically more efficient than proteins [1] - the laws of thermodynamics directly contradict "a calorie is a calorie"! Not to mention the fact that consumed protein is metabolized and stored differently than consumed sugars, which are in turn different from fats.

[1] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC506782/#__sec4ti...


> What part of the laws of thermodynamics imply calories in -> calories out?

The part where you restrict your assessment to more or less normal digestive function? Obviously if your stomach explodes or your intestine just plain stop working, caloric intake/deficit is now one of the least of your worries.

I think you actually hit the nail on the head here though, in using the word "imply". Calories in - Calories out doesn't give you an exact picture, but it comes reasonably close for the purposes of most people.

It's by no means a perfect understanding, but someone who is obese needs simple rules that can successfully get them started more than they need a perfect knowledge of the science involved.


"more or less normal digestive function?"

what is that exactly? I have twin girls, one is a full foot taller than the other. One is noticeably pudgier than the other.

They both eat differing amounts, and clearly pretty much the same kinds of foods is used in differing ways by different digestive systems.

what makes you think there is an establushed norm?

"Calories in - Calories out doesn't give you an exact picture, but it comes reasonably close for the purposes of most people."

Im not at all convinced that this is true. It sounds true, and it naturally appeals as a simple truth, but I haven't seen much evidence to support it.

From what Ive seen across a wide range of people, differing bodies process foods in wildly differing ways - some people fart or burp a lot, some people hardly ever, some people prefer eating large amounts once a day, some people prefer eating small amounts regularly. As a teenager I could consume mcdonalds like a horse, now a single burger sits like a lead stone in my stomach for hours.

Convince me that it is true?


Are your twin girls adults yet? Nutrition and diet are difficult while people are growing. Your body is actively building itself in a way that never happens again. You need larger quantities, of almost everything, than body mass would suggest. You're right, for children, it isn't simple calorie arithmetic.

That said, how disparate are the "differing amounts" they eat? Are they identical twins or fraternal? Lifestyle differences? There are a lot of factors that could produce the effects you're seeing besides "calorie arithmetic doesn't work".

The essence of telling people "calories in - calories out" is to favor a simple (i.e. "easily applied") rule over an absolutely correct one. While people are growing, the equation changes. Get all of your calories in the form of twinkies and your body doesn't get the nutrients it needs to process food, so the equation changes. Assume "normal" ranges for diet and exercise and it more or less works.

This is a fantastically complicated topic, but it is not immune to human nature. We like simple rules that generally work, even if they're full of loopholes and caveats. For people that are overweight or even obese, calories in - calories out is good enough to get started. There are a lot of factors in managing that equation (satiety, nutrient balance, impulse management) but I think a clear goal is a better start than dumping people in a sea of (correct) information.


Taubes shows those simple rules don't work (so many people have difficulty loosing weight) because the causality is backwards.


Ergo, give the obese people the rules and shut. up. about Thermodynamics.


I can agree with that opinion, but I also see the value in "appealing" to science.

People will believe all kinds of stupid things if you can imply that science has made truth of them. For the purposes of getting someone started this is a rather innocuous lie.


> metabolic pathways

well, here you go!

http://web.expasy.org/cgi-bin/pathways/show_thumbnails.pl


I agree that there are several factors involved in the process of absorption for "Calories in, calories out" to be taken as a sufficient guideline for losing weight. However, the point I think people try to make when they use it is that the raw amount of calories you consume are an UPPER BOUND for the amount of energy you have available.

I know that the actual values are hard even to estimate, but we only get energy from food: if you need amount X of energy to keep functioning and the raw total of energy contained in the foods you eat is less than X, you simply can't gain weight, "asymptotically" speaking. That's why people invoke thermodynamics here.


  In the end: calories in, calories out. Humanity hasn't defeated the laws of thermodynamics.
I think is a simplistic and problematic view of it. We are complicated machines. We can't process all types of input efficiently and without side effects. Any type of machine works differently depending on the source of energy. I can't put diesel fuel in my car and expect it to run the same way that it does on gas. Diesel fuel has energy just like gas but there is more to it than that.


> In the end: calories in, calories out. Humanity hasn't defeated the laws of thermodynamics. It's just a question of how easy and healthy it is to maintain a sub-maintenance caloric intake.

It is all about "calories in, calories out" but what on earth makes you assume that the human digestive system approximates the behavior of a bomb calorimeter? The whole article is about how the body extracts different amounts of the potentially available calories in food, and uses different amounts of energy to extract those calories.


> Humanity hasn't defeated the laws of thermodynamics.

But that doesn't mean what you think it means. Link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC506782/


Great article, thanks for the link. For those who don't want to wade through this technical and fairly lengthy article, here's a quick summary:

The people who say "a calorie is a calorie, and to deny that would violate the laws of thermodynamics" are arguing from the first law of thermodynamics (conservation), but misunderstand the second law (entropy). The article shows that if you take into account both laws of thermodynamics, then the statement "a calorie is a calorie" is actually a violation of the laws of thermodynamics.

The next two paragraphs are the conclusions of the article, quoted verbatim:

A review of simple thermodynamic principles shows that weight change on isocaloric diets is not expected to be independent of path (metabolism of macronutrients) and indeed such a general principle would be a violation of the second law. Homeostatic mechanisms are able to insure that, a good deal of the time, weight does not fluctuate much with changes in diet – this might be said to be the true "miraculous metabolic effect" – but it is subject to many exceptions. The idea that this is theoretically required in all cases is mistakenly based on equilibrium, reversible conditions that do not hold for living organisms and an insufficient appreciation of the second law. The second law of thermodynamics says that variation of efficiency for different metabolic pathways is to be expected. Thus, ironically the dictum that a "calorie is a calorie" violates the second law of thermodynamics, as a matter of principle.

The analysis above might be said to be over-kill although it is important, intellectually, not to invoke the laws of thermodynamics inappropriately. There are also, however, practical consequences. The seriousness of the obesity epidemic suggests that we attack it with all the means at our disposal. Metabolic advantage with low carbohydrate diets is well established in the literature. It does not always occur but the important point is that it can occur. To ignore its possibilities and to not investigate the precise conditions under which it appears would be cutting ourselves off from potential benefit. The extent to which metabolic advantage will have significant impact in treating obesity is unknown and it is widely said in studies of low carbohydrate diets that "more work needs to be done." However, if the misconception is perpetuated that there is a violation of physical laws, that work will not be done, and if done, will go unpublished due to editorial resistance. Attacking the obesity epidemic will involve giving up many old ideas that have not been productive. "A calorie is a calorie" might be a good place to start.


That article underestimates the level of muddled thinking that exists.

There are people convinced that they can gain weight on a hypo-caloric diet. Of course this is easy to do, drink a glass of water, but that isn't what the muddled thinkers mean.


>In the end: calories in, calories out.

If you're just talking about "weight loss" then yea, that's right, but you don't address body composition at all here.

If you just wanted to "lose weight", then you could chop off an arm and BOOM, you just lost weight. What MOST people want to do is to burn and lose fat, NOT weight - they just express it differently.

If it was just calories in vs calories out, I could drink 3000 calories of vodka a day and still be okay as long as I burned off 3100 calories, and we all know that's not the case.


Yikes, that'd be nearly two fifths of vodka. I'm could be naive here, but I'm not sure the hardiest of alcoholics can put that away in one day.

I get the point, mind you, just shocked by how much alcohol that is...


Downvoted for opening with a (double) argument from authority.

For your "more scientific" view, you offer assertions without citing any supporting evidence. So, as is, your statement is an opinion, as is so much nutritional advice.

Hope your startup is based on more logic and less conventional wisdom than shown here.


I go with what the PhDs doing the on-the-ground weight-loss studies say, not the anecdote of some person on the internet who's read a book or two.

Programmers hate it when people question them, you'd think they'd extend the same professional courtesy and benefit of the doubt to other academic and professional disciplines.


Please provide citations if available.

It is entirely possible there is a well-understood theory with masses of supporting evidence that for whatever reason the public don't think is sexy enough to be true. This is the problem with evolution for example, where there is the data behind it but the US public still think its controversial.

Note: If Person A provides a book reference (secondary evidence) and Person B provides no specific reference (no evidence) then I am biased towards Person A. If Person B could provide a reference to some research (primary evidence) then I am biased towards Person B. If Person B ends with some general slur against my profession after someone asks for a reference, Person B loses the bias.


http://news.ycombinator.com/item?id=4441289

My comment here lays out some ground facts/truths.

Respond there for questions.


Calories are a measure of heat. Not Energy. You measure calories buy burning the food in question and measuring how hot it raises the temperature of a given amount of water.

Magnesium burns a lot hotter than corn therefore it has far more calories than corn yet eating a pound of magnesium a day is not going to make you as fat as a pound of corn a day.

So please stop with the "calories in, calories out" simplification.


> Calories are a measure of heat. Not Energy.

Calories ARE a measure of energy. One calorie = 4.2 joul = 4.2 wattsecond.

A calorie is defined* by the amount of energy needed to heat 1 gram of water by 1 degree celsius under a pressure of 1 temperature. But heat is energy, and a calorie (as well as a joul) are a measure of both.

> So please stop with the "calories in, calories out" simplification.

That part is true: Calories in, calories out is wrong, as has been shown repeatedly over the last 50 years. But somehow it is still the religious belief of many.


You're correct.

I should been clearer. I meant "energy" in terms of energy the body can use. E=MC^2 means everything can be considered energy. But can something be used as energy for a specific process, like making a body fatter, is another issue.

We agree, calories do not measure how much energy the body can extract or use from a piece of food. They only measure how much energy is produced burning the food. Bodies don't burn food, they digest it. So measuring calories doesn't say anything about whether a particular substance can be used by the body.


> They only measure how much energy is produced burning the food. Bodies don't burn food, they digest it.

You need to review your biology. The most common energy extraction process in the body actually IS, at its essence, oxidation - a.k.a "burning". And that's why people did the calorimeter burning measurements. The other common process is essentially fermentation, but in a healthy human, the vast majority of energy is obtained from food through oxidation.

> So measuring calories doesn't say anything about whether a particular substance can be used by the body.

It puts an upper limit because (as far as we know) oxidation is the most efficient process the body uses, but not a lower limit.

The body may flush out anything without any form of digestion, fat conversion, or oxidation (thus no energy extraction), even if it is pure sugar. Furthermore, the enzymes used by the body for oxidation are very specific. The most abundant carbohydrate around us, cellulose (wood and paper are examples), cannot be digested / oxidized / burned by the human body.


     Taubes isn't taken seriously by most dieticians and 
     nutrition researchers we talk to
That's an appeal to authority that dismisses the many studies given as reference in the Taubes book, studies which have results that are contrary to popular wisdom.

One of those studies involved a comparison between a group of people that were placed on a low-carb diet and the weight loss was more efficient than in the other group placed on a high-carb diet that ate less calories.

Of course, when it comes to nutrition, most studies are flawed because you can't do double-blind studies and because controlling the variables involved is hard. However, that's one reason why I go by my gut feeling and completely ignore "most dieticians and nutrition researchers", at least for now.

And I'm doing that because those same dieticians and nutrition researchers have recommended and are still recommending high-carb diets, with complete disregard to the health issues associated with consuming a diet rich in sugar, starch and deficient in proteins, fats and certain vitamins (the fact that we are omnivores that need a balanced diet should have rang a bell, but no).


Not to mention, counting calories is just painful. Have you ever really tried to do this? Frankly, it just sucks.

Has any other culture in history EVER counted calories? I'm betting "no" considering the calorie is a relatively new concept (1842). And yes, somehow they managed not to have the obesity problems we have today.

>http://en.wikipedia.org/wiki/Calorie


Counting calories is a great way to lose weight actually. Every time you go to eat something you think "Do I really want to record this in my food log?" Then you say no and don't eat it. I ate drastically less as a direct side effect of trying to count calories.


I wonder if can affect variety of the diet though? "I have no idea how many calories this salad is, let me eat that well measured donut instead and be done with the paperwork" would totally be my train of thought...


This never addresses the mentality of "eating better" instead of simply "eating less."


> "counting calories is just painful. Have you ever really tried to do this?"

Yes. It is (or at least was) the core mechanic of Weight Watchers (converted to a "points" scale), and it worked pretty damn well.

For me, it was a pain for about 2 weeks. By then, I'd figured out all of my common food items, and how to cook dishes with reduced calories but that were still plenty filling.

As a result, I now know how to structure my diet to get the same benefits without actually having to count.


I considered calorie counting too hard to do. Then smartphones and apps came to be. I've been using the myfitness app for several months, and it's definitely bearable.


In the past, most of the people didn't spend time watching TV while eating junk food.

And yes, I do count calories. I'm committed to staying fit, and counting is not an option.


I'm philosophically opposed to the phrase "calories in, calories out". True, we can't violate thermodynamics. However, the real important thing is calories absorbed, and how those calories affect metabolism, calories out.

Not as poetic, but you said it yourself - 300 calories of oreos are not equal to the same calories of chicken. And wood sure has a lot of calories (right?) but chew it up and eat it and you're not gonna get many of them absorbed. And some food triggers more of an insulin response which affects what your body does with the calories. It conveys the wrong point to the person who doesn't learn more to say "calories in, calories out" even though at some level of course it's thermodynamically sound.


There is definitely a scientifically provable correlation between caloric intake and weight gain. It's somewhat causal in that if you suppress calories weight gain (growth) is reduced.

The tricky part is that causality runs both ways. When a child grows, they take in a caloric surplus. If you surpress caloric intake, the growth will be suppressed. It's the same for plants too. Block the sun & they will grow slower.

So (according to good/bad calorie theories) it's not that calorie accounting is incorrect. Take in fewer calories and you'll lose weight. It's that it misses the point. The correct question is why is your body growing (and pursuing the calories necessary to fuel it).

*My own pet theory is that foods aren't inherently bad or unnatural for us to eat. We're just wired to build different bodies depending on available food sources. Mono-croppers need to survive bad harvests & hungry winters. Sugary fruits usually aren't available for very long, it might be good to build up a reserve while they are.


> Humanity hasn't defeated the laws of thermodynamics.

Human body does not extract 100% of energy from food, and waste that comes out is not calorie free. So it is not simple 'calories in, calories out'


It's ok, Taubes doesn't take most dietitian and nutrition researchers seriously either :) (thankfully, imo). -demagogue


What's the startup? Do you have a URL? Thanks.




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