Thermodynamics and weight loss

I think anyone who understands the first and second laws of thermodynamics will see that a HIGH CARB / LOW FAT diet OR a LOW CARB / HIGH FAT diet can be beneficial in weight loss, I will attempt to explain why via the laws of physics.

The first law of thermodynamics:

"In all cases in which work is produced by the agency of heat, a quantity of heat is consumed which is proportional to the work done; and conversely, by the expenditure of an equal quantity of work an equal quantity of heat is produced."

~Rudulf Clausius, 1850

Or:

In a thermodynamic process, the increment in the internal energy of a system is equal to the difference between the increment of heat accumulated by the system and the increment of work done by it.

~Rudulf Clausius, 2nd translation

To state the law simply, “You cannot get something from nothing.”

Energy cannot be created or destroyed, it can however be stored. And this is the reason those who understand only the first law, while having no knowledge of the 2nd, mistake this to mean “a calorie is a calorie”.

Basically in any internal incremental process, the change in the internal energy is considered due to a combination of the heat added to the system (calories being a unit of measure for heat), and work done by the system (in fitness, usually defined as a combination of maintaining metabolic functions, and exercise and work combined).

Therefore, the formula as it applies to the human body in terms of fat storage, may appear like this:

dU=sD-sW

Where (d=change) and (U=Internal Energy, energy stored in fat, muscles, liver, etc...), (s=supplied)(D=dietary intake) and (W=work done via maintaining metabolic processes, work, exercises, etc…)

In terms of numbers, if we at 3000 calories, used 2000 to maintain life, and 500 doing work and exercise we would have

(d=+500 calories) = (diet = 3000 calories)-(work=500 calories, maintenance=2000 calories)

See a problem here? Just wait.

The above formula makes sense, and we see it ALL THE TIME. But it is fundamentally WRONG and violates the 2nd law of thermodynamics.

The 2nd law of thermodynamics is not called the 2nd law because it is less important, but rather because it was discovered 2nd. It is also inviolate in all of nature.

The 2nd law is why perpetual motion machines are impossible and nobody has ever successfully invented one despite numerous attempts.

The second law states as follows:

“No process is possible in which the sole result is the absorption of heat from a reservoir and its complete conversion into work.”

~Lord Kelvin

In other words, whenever you transfer eat, such as transferring heat from propane into air in your furnace to heat your home, you will simply never have 100% efficiency. 99% efficiency furnaces burning 100 calories of heat, will put 99 calories of heat into the air. The remaining 1% is not destroyed, as that violates the first law, but it is NOT transferred into the system either.

Let’s compare to the body and fat storage and calorie usage.

Food contains calories, calories must be “released”, in other words, the body must act on them to release them and use them. Now, these do not actually become heat in many cases, but rather, the calories change forms to become different substances readily available to be converted into heat.

Thus, when you eat a piece of bread, the body slowly breaks the carbs down into glucose (except the fiber which passes through). It is this glucose it holds at the ready to convert into energy rapidly during moments of high need.

So, the bread is converted into glucose in a less than a 100 percent efficient process as defined by the 2nd law, and then when needed, energy is released in another less than 100 percent efficient process, as defined by the 2nd law.

Now, the process of breaking down bread into energy, via these two steps, is fairly efficient metabolically, in that when you eat 120 calories of bread, about 80% of the none fiber carbs in it eventually becomes available as glucose, which is again burned when needed for its energy content, at over 80% efficiency. So using 80% both times for efficiency to keep things simple, this is an overall efficiency of .8 x .8 = .64 or 64% (This example is illustrative).

Now, my 50 year old oil furnace in my house is currently more efficient than that. Funny, two fairly efficient processes combine as steps in a larger whole to become an somewhat inefficient process. Consider that many metabolic systems encompass many steps and you can see why we radiate heat all day that would otherwise be useable energy by our body.

So assuming that we ingest 1000 calories of pure carbs, which convert into glucose, then convert into energy on demand, we would be able to get 640 calories of useable energy (again, this is illustrative). The 360 unaccounted for calories are NOT STORED as this would violate the 2nd law and give us a 100% efficient system. These are not destroyed either, as their destruction would violate the first law. Where these end up is in heat, or in the residual substances that our body excretes or emits at the end of the day. We release heat when working out hard, but and also yes, your poop and your urine, technically have calories and contain that leftover cast off material that also hold calories resulting from metabolic burn. And if anyone has had the misfortune of seeing that terrible human centipede movie, you can verify that poop indeed has calories. Urine can as well, in the form of unused glucose or ketones.

So how do we make the first law gibe with the second law?

Where in the formula do we plunk in the efficiency of a system, which defines how much energy is unavailable to the system and is returned to the universe?

dU=sD-sW

This formula above is correct and abides by the first law, and not the second. To modify it to abide by the 2nd, we need to add one more element, entropy, and to round it out, we should add efficiency.

Thus

dU=sD-sW

becomes

(dU x E) =sD -(sW x E) – Entropy

Where (E=efficiency rate) and (Entropy = loss of energy to the universe* as per the 2nd law)

*In truth, the energy is not truly lost; it is just in a state no longer useable by whatever system gave it up. Hence, an oil furnace exhausts fumes which can be recaptured and burned in other systems with their own efficiency concerns.

The blog of Dr. Micheal Eades correctly states:

“The second law of thermodynamics says that the entropy of the universe increases during any spontaneous process. What this means is that it is impossible for a system to turn a given amount of energy into an equivalent amount of work. It is this second law that is really the ‘a calorie is a calorie’ law, and, in fact, the second law shows, in terms of weight loss at least, that a calorie isn’t necessarily a calorie.

“The second law is a dissipation law in that it says that in any reaction that is irreversible (most of the chemical reactions that give us life) there is a loss or dissipation of energy in that reaction. If substance A converts to substance B via a chemical reaction in the body, then substance B has a lower energy than substance A. In other words energy is lost to the universe in that reaction. There is no reaction that doesn’t end up without a loss of some energy to the universe. This loss of energy is called entropy.”

I see no need to paraphrase the above when the above was so perfectly written.

The real definition of entropy as it applies to the body is simply energy given up that the body cannot use without re-ingesting somehow and trying again. There are a few ways the body gives up energy.

The human body radiates heat. When a person is placed on a high protein diet they actually get hotter, and this has been tested over and over and is not in dispute. This is due to inefficiency in the way the body releases energy from protein. Instead of getting 100 percent useable energy, the body radiates a lot of the energy as lost heat, and back to the universe it goes, in accordance with the 2nd law.

Excrement has calories, as do substances emitted in the urine. These are residues of our metabolic processes and the chemicals left over are filtered out by liver and kidneys and ejected despite having useable energy. This energy, locked into our leavings, flushed away, returned to the universe, as per the 2nd law.

So, in conclusion, the goal here is not to explain why a low carb diet is superior, but rather to clarify for those who misquote, and misunderstand the first law of thermodynamics as it applies to the body.

It is the 2nd law which is of paramount concern, and the second law which applies to the body.

The formula often presented

Calories stored = calories in – calories spent

…is fundamentally flawed as it violates the 2nd law of thermodynamics. To provide a quote on that possibility, let me introduce Ivan Bazarov, who wrote a certain well used physics text.

“The second law of thermodynamics is, without a doubt, one of the most perfect laws in physics. Any reproducible violation of it, however small, would bring the discoverer great riches as well as a trip to Stockholm. The world’s energy problems would be solved at one stroke. It is not possible to find any other law (except, perhaps, for super selection rules such as charge conservation) for which a proposed violation would bring more skepticism than this one. Not even Maxwell’s laws of electricity or Newton’s law of gravitation are so sacrosanct, for each has measurable corrections coming from quantum effects or general relativity. The law has caught the attention of poets and philosophers and has been called the greatest scientific achievement of the nineteenth century.”

How does this apply to low carb diets?

Low carb diets, and I admit, this is my personal take on it, manipulate the efficiency of the equation.

(dU x E) =sD -(sW x E) – Entropy

So (E = Efficiency), we can store energy with certain efficiency, and that efficiency level is controlled by hormones such as insulin, leptin, glucagon, etc… and dietary composition, for examples, free fatty acids cannot really be stored in fat cells without carbs being present and all the energy is in free fatty acids, and carbs cannot store free fatty acids in fat cells if free fatty acid is not present and all the energy is in carbs.

We can burn energy with certain efficiency, which is determined in our bodies, in large part by what the energy is stored in, and what processes are used to release that energy.

Low carb diets manipulate the efficiency on the storage side of the above equation (dU x E), by removing the tool that makes the storage system efficient, that being carbs.

Another approach is to go on a low fat diet which provides ample carbs to aid in free fatty acid storage, but very little free fatty acids to actually store. And many cultures have done well on this traditional method, such as tropical indigenous peoples who survive on plentiful sweet fruits and proteins mostly coming from lean sources such as fish, monkeys, snakes, etc…

Both a low carb, high fat diet, and a high carb, low fat diet, can aid in weight loss by making the fat storage process less efficient, simply because to be at its most efficient, fat storage requires both those nutrients to be present in an ideal ratio.

Which brings me to another important point…

Knowing all of the above and manipulating the fat storage side of the equation, the very worst thing one can do is to eat a good amount of carbs, and a good amount of fat, if trying to lose weight.

For this reason, foods like fried chicken are the perfect food for weight gain. You have an oil fried, high fat product, coated and battered in starch. It is the ideal recipe for weight gain. And in that, I think both low carbers and carb lovers would agree.

Sadly, our current food guides recommend ratios that provide exactly this destructive formula of “low to moderate fatty proteins, and limited healthy fats, with a diet rich in complex carbohydrates.” This, to me, is a recipe for obesity and should be avoided by both carb lovers and low carb dieters. This dietary formula makes the fat storage side of the equation highly efficient, forcing a much greater reduction in dietary caloric intake. Calorie restriction will still work, but more of it is required to achieve less storage of energy in the body, as fat. Perhaps this is why we get so many hungry dieters that are not losing weight. Calorie restriction is their only tactic, and as such, must eat less to achieve the same results as those who follow one of the two other available paths.

The carb lover/low fat approach is a very valid approach to enhancing weight loss. And many have lost weight with this in conjunction with calorie restriction.

There is of course another part of the equation we can easily manipulate, besides the (E=Efficiency), and that is the sD, or supplied by diet

(dU x E) =sD -(sW x E) – Entropy

Obviously, if we supply less energy into the system, less will be available to store.

So, if we add more food of any type, we make more available for work, and more available for storage.

We can also manipulate sW or, or supplied work by lifestyle changes including exercise.

If we increase exercise, we reduce fat storage OR increase dietary need, or a little of both.

So knowing all of this, to state a calorie is a calorie is fundamentally incorrect, the conclusions drawn by those who state this are not entirely incorrect. Just because you take the wrong road to Boston does not mean you won’t reach Boston. To quote my boss at work, just because it works, doesn’t mean it’s right.

I hope this paints a more complete picture of physics and how it applies to gaining and losing fat.