Alan Aragon Research Review ~ Answering some questions about Thermodynamics

I'm once again honored to contribute to this month's edition of Alan Aragon's Research Review.  This time I was interviewed and answered the following questions:

This is premium subscription content, but AARR is always worth the price in my opinion!   Plus you'll get access to all archives (including past contributions from yours truly from the May-June issues of 2013 and 2014).

I missed getting to have my dedication in there, as I didn't think of it until after submission, but I wanted to dedicate the article to my grad school advisor Dr. Owen F. Devereux.   Dr. D died a couple years back or I would have been proud to send him my writings on thermodynamics.  He wrote a book called Topics in Metallurgical Thermodynamics that was his main area of research.  I called it the bane of my grad school existence, but really it wasn't.  Through applying the concepts of that book to my research I really learned and understood thermodynamics.  Folks often wonder what my seemingly irrelevant advanced degree has to do with any of this nutrition stuff.  Well, we applied the concepts to corrosion which is electrochemistry.   Biochemistry is living electrochemistry.  This means it involves enzymes and reaction coupling to get chemicals to do things they wouldn't otherwise do spontaneously.  But in the end the concepts are the same.  If you're a subscriber, I hope you'll enjoy!  If you're not, you might want to consider subscribing now ...


Bris Vegas said…
"Folks often wonder what my seemingly irrelevant advanced degree has
to do with any of this nutrition stuff. Well, we applied the concepts
to corrosion which is electrochemistry. Biochemistry is living
electrochemistry. This means it involves enzymes and reaction coupling
to get chemicals to do things they wouldn't otherwise do spontaneously.
But in the end the concepts are the same."

By your reasoning carpentry and orthopaedics are the same because they both involve using hammers, saws, drills and screws.

done five years of biochemistry (including a research masters). From
experience I'd argue that electrochemistry is a very minor component of
modern biochemistry. Real world biochemistry is mostly applied biology.
It is not the dry theory and metabolic pathways contained in textbooks.

reality is that NONE of the nutrition bloggers have any real expertise
in the field. At best they have expertise vaguely connected to some
field of nutrition research (eg medicine, biochemistry or neuroscience).
If you want to be a nutrition EXPERT you need a PhD and be willing to
spend decades as an ACADEMIC researcher. [There is no such thing as a
'private' researcher.]

You can't be an expert in any field just
by reading textbooks and scientific papers. The vast majority of what
you need to learn comes from practical experience and feedback from
carbsane said…
Your educational background seems to have changed. I thought you were a food scientist. Thanks for your input, I'll file it appropriately. You might want to pass this along to Loren Cordain ;-)

If you've really studied biochemistry then you wouldn't make the argument you do about the actual chemistry part. The thermodynamics is the same. Biological systems run on electrochemical "engines". The "bio" part doesn't change the rules of the game.
Jane Karlsson said…
"You can't be an expert in any field just by reading textbooks and scientific papers. The vast majority of what you need to learn comes from practical experience and feedback from colleagues."

When I was doing research, the vast majority of what I needed to learn came from studying the literature. Without that you don't know what questions to ask, and if something unusual turns up you fit it in with what your supervisor thinks. This kind of thing can be disastrous for scientific progress.

Many years ago scientists thought modern disease was caused by 'bad genes' rather than poor diet, because that was what Richard Dawkins said, and nobody bothered to read the genetics literature to find out whether he was talking nonsense or not. I once said to him 'genes don't work like that', and he said it wasn't his problem, it was for the geneticists to sort out. I was astonished. Did he really think reading the literature was unnecessary? Yes, he did.
sautterron said…
Why would you bother with the things you can't measure in practical, everyday circumstances? How would you measure the energy out for example: anlyzing the excrements (weight, density, structure), constantly measuring temperature difference between you and your environment, including isolation factors from your clothing in your calculations? How about the energy in - one from the sunlight shining on you: should we constantly wear light meters, include area covered by clothing and uncovered one in calculations? Even simpler examples - how many calories has the mystery lunch that your grandma made for you?

Alan Aragon has it easier - he trains sportsmen. Sportsmen can always compensate for the impossibility of doing calculations via some additonal crazy excercise level, or abstaining from one for a while. And excercise is easier to tabelarize than "conditions of life" like the weather, sunlight, diarrhea etc. Metabolic ward studies have it easy - as everything is in the lab. Normal people in everyday life can't just use this thermodynamics of their bodies for anything useful.
carbsane said…
The point about thermodynamics is not that we MUST be able to account for CICO, or that we NEED to account for CICO. Rather that it CAN be, and it HAS been by Atwater and many after him. The point of my article, that I won't discuss in depth because I don't know how many here even subscribe to AARR, was answer to (1) First Law applies perfectly well to open systems, and (2) Second Law offers nothing more to explain that which is beyond the scope of First Law. Furthermore, a point I've made here often, that many arguments citing the Second Law are actually First Law applications anyway.
carbsane said…
I would add that a goodly chunk of what I learned in grad school was through reading literature and the texts, and not in some geek klatch with colleagues every other day. If someone manages to do a PhD without an extensive review of what's out there in the literature to date, their institution should probably be investigated.
sautterron said…
So let's "manipulate energy balance for weight loss". 2500 kcal/day = 10,46MJ/day. Assuming lifetime of 85 years (around 31k days) it would give around 0,32TJ of energy per lifetime. E=mc^2, so m=E/c^2. c^2 (in m^2/s^2) is about 9E+16, so the total mass los from producing 0,32TJ of energy is 3,6 mg.
3,6mg = lifetime weight loss from conversion of weight to energy. That's not much. Laws of thermodynamics are about energy, and this is the only weight loss from energy creation that you have.

Rest of weight fluctuations come from moving things around. Eg. someone eats fat, fat is incorpodated into the tissues, this leads to additional 20kg of weight, then this person gets a liposuction and looses eg. 25kg of weight. See - high weight fluctuations with no "thermodynamics" involved whatsover. Many "pathways" of the same type exist - the most obious one being water, that flows through us even naturally. Same with protein - eg. incorporated into the skin, then the skin is shredded (it location becomes outside of the body). Again - no thermodynamics, while weight changes.

Of course some of the flows that cause weight changes are related to the energy production via chemical reactions. But this is not about "thermodynamics" but fulel supply management, and waste removal! The power plant analogy would be the coal storage, and sludge storage rather than the actual energy production itself. So thermodynamics doesn't apply here, its just logistics.

Converting mass that goes through us to energy units (calories) via some voodoo process in order to calculate... mass changes looks like a nonsense. If you really want to balance inputs and outputs then measure mass itself - at least you don't commit a thinking fallacy then - at least the units you count in are real, and describe what physically happens.
carbsane said…
Not to be rude here, but you are in desperate need of subscribing to AARR to read my interview. I have covered these concepts here before, but the interview is more focused (though still lengthy). I'm a bit pinched for time at the moment so try the Thermodynamics label or just the search on the side bar.

Many of your arguments are wrong and/or irrelevant in the overall context and I just don't have the time to answer this here in a post which is basically an announcement.
Radhakrishna Warrier said…
In my humble opinion, Einsteinian equation e=mc^2 is irrelevant in the discussion on the energy consumption and weight gain/loss as applied to the human body. The human body does not get energy by breaking down or fusing together atoms. The energy is obtained from chemical reactions which convert potential chemical energy stored in chemical bonds to other forms energy such as electrical, physical, and thermal. Here, mass is not converted to energy, or vice versa, and hence the irrelevance of e=mc^2. When wood burns, the remaining ash is much lighter than the original wood becuase a good portion of the wood gets converted to carbon dioxide and escapes to the atmosphere. If you add the weight of the CO2 that escaped, the result would be more weight than the original wood because in the process of burning, atmospheric oxygen got combined with the carbon in the wood to produce CO2. But there is no net increase or decrease in the total mass of the constituents that participated in the chemical reaction. The chemical reaction just converts one form of energy into another - stored chemical energy into say thermal.

When the human body burns its fuel (obtained from food or stored previously in the body) the fuel becomes CO2 and water which are quickly expelled from the body, and hence the body loses weight. If you burn more fuel than what was obtained from food (in this case the body burns a part of the previously stored fuel in addition to that obtained from food) there is a net weight loss. If the body burns less fuel than is obtained from food, there is a net weight gain.


Morris39 said…

I wonder if you agree with the below statements:

CICO applies without doubt in a conceptual sense but with the proviso “ all else being equal”. The discussion is usually about calorie intake and fat gain and almost always “all else” is equal. Sometimes (seldom) it is not ; e.g growth spurts in adolescents, or in very ill people.

2. Laws of Thermodynamics as applied to living organisms are not possible in a practical sense. We cannot (with present knowledge) formulate equations in this field.
carbsane said…
Perfect Rad.

I'm going to have to add exfoliating to the Calorie book tho. :-)
carbsane said…
Again, it's difficult to discuss these things in an announcement for an article that's not on this site. But quickly:

1. The discussion may be about calories and fat gain (or loss) but obviously it holds always and in every living being. Obviously during growth we use some intake to create that mass, some add more lean with fat and/or lose more lean with fat, but the vast majority of excesses and deficits over the long term come and go from fat mass because that's how we are physiologically designed to store energy.

2. If the laws of thermo didn't apply NuSI couldn't do their metabolic chamber study ;-) Just because exact equations can't be formulated doesn't mean that approximate ones are impossible. Why should we bother putting MPG ratings on cars? Exact equations on engine efficiency are impossible, right?
Morris39 said…
It seems we are in agreement on 1. but not on point 2. Equations need to be complete (i.e. include all important variables) to be useful but are only exact in textbook examples. In practice (engineering) equations are always adjusted (fitted) to the particular circumstances. In biology the variables are not fully known (incomplete) and their interdependence likely varies in unknown ways. So equation are not used in biology because they cannot be written. To someone with a basic understanding of biology and thermodynamics at undergrad level, the CICO debate (if there is really one) is not interesting or necessary.
An interesting question is how energy is partitioned and possibly optimized in our bodies. An approximate mass/energy balance may be possible by experiment. Why this is never discussed in research is an interesting question in itself.
carbsane said…
The debate is not necessary because there should be no debate Morris. Anyone with a basic understanding of physical laws knows that it has to hold. And it is not an impossible task to identify all of the CI and CO terms that need to be addressed.

Sautterron brought up exfoliation as a term in CO I hadn't yet considered. Perhaps because skin sloughing would be an infinitessimal term included in REE.

Alan doesn't require a lifetime commitment. $10 gets you access to all back issues. Perhaps worth your investment. I'm sorry but I can't engage further here and you'll have to comment on relevant content on this blog if you feel it's worthwhile.
sautterron said…
@Radhakrishna Warrier - on chemical reactions "Here, mass is not converted to energy, or vice versa, and hence the irrelevance of e=mc^2. [...] there is no net increase or decrease in the total mass of the constituents that participated in the chemical reaction"

Actually the energy in chemical reactions is produced from the loss of mass. A good explaination is here:

"It's a really common misconception that E=mc2 only applies to nuclear reactions.But E=mc2 applies every time energy is given off or gained, whether it's in a chemical reaction in a mobile phone battery, or a good old-fashioned kick of ball. [...] For example, chemists know that when methane (CH4) is formed from carbon and hydrogen atoms, energy is released. C + 4H > CH4 + energy

They may not know that methane is 0.000031 per cent (2x10 -8 amu) lighter than the combined mass of the individual carbon and hydrogen atoms that form it."

Humans or other animals are not high-power systems, actually we are very low-power per volume. What we have a lot we have this constant flow of matter through us, part of which you described (CO2,.H2O excretion). The amount of matter is called mass, and it's measured in kg. Disturbances (eg caused by some problems) in that flow cause weight gain or weight loss - again measured in kg. Talking about weight gain or loss in "calories" and thinking that it is "thermodynamics" is both an unit error and a partial cateogry error.
One example I gave where the category error is clearly visible is:
fat intake -> fat storage (weight gain) -> liposuction
in which there's no conversion to energy, while substantial weight changes occur. Thus speaking in "calories" about "thermodynamics" then is a visible category error.
Notice it's a category error if you count all food ingested as "Calories" as most do; if you somehow could isolate what food really gets transformed into the energy, and apply calories only to this - this would make more sense. Possibly couldn't be done in practice for a single individual, due to too many things to measure. Statistical averages of it for a large populations - maybe.
carbsane said…
From your ABC article:

>>> Chemists can spend entire careers ignoring E=mc2 because the changes in mass in chemical reactions are so small they're impractical to measure. The only places where we deal with enough energy to see changes in mass are in nuclear and particle physics experiments. <<<

So why are you going on about it as if it has any meaning?? The meaningful energy associated with chemical reactions is bond energy. All macros contain certain potential calories (when burned) per gram. When they are burned, the grams are exhaled as CO2. Liposuction removes lipid (and other stuff) without it being burned off - like siphoning gas from a car. No thermodynamics needed in that case, just as there are no thermodynamics essentially to fat gain when ingested lipid finds its way into fat cells.
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