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06/12/2022

Can Thermodynamics Explain Why We Gain Weight?

Contents

  1. What does the first law of thermodynamics tell us?
  2. The human body is a mass of chemical reactions 
  3. Calories eaten is not the same as calories the body takes in. My thoughts
<The bottom line>

First, please read the following article. 
The Calorie Principle and Weight Gain; The Causality Has Been Obscure

According to Gary Taubes, it was first claimed in the early 1900’s by Carl von Noorden (a German diabetes specialist) that we gain weight because we take in more calories than we expend. This argument has continued to the present day, and we are told that taking in too many calories and lack of exercise are the causes of weight gain. 

This time, I would like to share the “law of thermodynamics,” which was said to be the basis for that theory. Mainly quoted from the book, it is so interesting that I think it is worth reading.
  

1. What does the first law of thermodynamics tell us?

"There are three laws of thermodynamics, but the one that the experts believe is determining why we get fat is the first one.

This is also known as the law of energy conservation: all it says is that energy is neither created nor destroyed but can only change from one form to another.

Blow up a stick of dynamite, for instance, and the potential energy contained in the chemical bonds of the nitroglycerin is transformed into heat and the kinetic energy of the explosion. 

Because all massour fat tissue, our muscles, our bones, our organs, a planet or star, Oprah Winfreyis composed of energy, another way to say this is that we can't make something out of nothing or nothing out of something.

This is so simple that the problem with how the experts interpret the law begins to become obvious.

All the first law says is that if something gets more or less massive, then more energy or less energy has to enter it than leave it.

It says nothing about why this happens. It says nothing about cause and effect. It doesn't tell us why anything happens; it only tells us what has to happen if that thing does happen. A logician would say that it contains no causal information.

packed place

Imagine that, instead of talking about why we get fat, we're talking about why a room gets crowded.

Now the energy we're discussing is contained in entire people rather than just their fat tissue.

Ten people contain so much energy, eleven people contain more, and so on. So what we want to know is why this room is crowded and so overstuffed with energy- that is, people.

If you asked me this question, and I said, Well, because more people entered the room than left it, you'd probably think I was being a wise guy or an idiot.
Of course more people entered than left, you'd say. That's obvious. But why? And, in fact, saying that a room gets crowded because more people are entering than leaving it is redundant-saying the same thing in two different ways-and so meaningless.


Now, borrowing the logic of the conventional wisdom of obesity, I want to clarify this point.
So I say, Listen, those rooms that have more people enter them than leave them will become more crowded. There's no getting around the laws of thermodynamics.

You'd still say, Yes, but so what? Or at least I hope you would, because I still haven't given you any causal information. This is what happens when thermodynamics is used to conclude that overeating makes us fat.

eating snack

The National Institutes of Health says on its website, “Obesity occurs when a person consumes more calories from food than he or she burns.”

By using the word “occurs,” the NIH experts are not actually saying that overeating is the cause, only a necessary condition. 

They're being technically correct, but now it's up to us to say, Okay, so what? Aren't you going to tell us why obesity occurs, rather than tell us what else happens when it does occur? "

(Gary Taubes, Why We Get Fat, 2010, Pages 73-75 )

2. The human body is a mass of chemical reactions 

"The first law states that energy can neither be created nor destroyed. In other words, energy can be converted from one form to another, but the total amount of energy in the universe remains constant. How might this law apply to weight management?

Suppose someone has stable weight over time. The first law dictates that, in theory, the number of calories consumed by this individual in the form of food is equal to the calories the individual expends during metabolism and activity. In other words, 'calories in = calories out’.(*snip*)

However, the first law of thermodynamics actually refers to what are known as ‘closed systems' -ones that can exchange heat and energy with their surroundings, but not matter. Is this true for human beings? 

chemical reaction

Actually, no: the human body does indeed exchange matter with its surroundings, principally in the form of the food (matter in) and as waste products such as urine and faeces (matter out). 

Also, technically speaking, the first law refers to systems in which chemical reactions do not take place.

But the human body is essentially a mass of chemical reactions. So, here again, the first law of thermodynamics cannot apply where weight management is concerned.

(Dr.Jone Briffa,Escape the Diet Trap, 2012, pages 63,64  )

3. Calories eaten is not the same as calories the body takes in. My thoughts

Two authors have made excellent points about the relationship between thermodynamics and weight management. Based on those thoughts, I would also like to mention two points about the relationship between thermodynamics and my theory.
  

(1)What constitutes "caloric intake" 

I also basically believe that if a person has a stable weight over the years, then "the energy consumed  and the energy expended for basal metabolism and activity,etc." must be balanced.
The question, however, is: at what point have we "taken in" energy? 

If we calculate calories at the point we put food in our mouths and consider it "calories consumed," then it is no wonder that for many people it is not balanced with the energy expended.

This is because, as Dr. Briffa pointed out, our bodies are not "closed systems.” If we consider energy absorbed from the gut to be "calories ingested," then it should be considered more of a "closed system."

▽Let's take the example of calcium in milk.

From experience, we know that it is not always true that the more milk we drink, the more calcium we take in and the stronger our bones will become.

Just because a bedridden old lady drinks five glasses of milk a day every two hours every day, does not make her bones stronger; in fact, it sometimes has the opposite effect. Even with just a glass or two of milk a day, exercising more and feeling hungry can increase absorption rate and make her bones stronger. 

In other words, it is not the amount of calcium drunk, but how much calcium is absorbed through the intestines that is balanced against the amount of calcium used in the body(some of the calcium in the blood can be excreted as urine). 

As Dr. Briffa pointed out, our bodies are "a mass of chemical reactions," so what is not absorbed ends up outside the body in the form of fecal matter. 
  

(2) When energy intake increases

Based on my intestinal starvation mechanism concept, even if a person who has maintained the same weight over the years, significantly reduces their usual caloric intake (e.g., about two thousand kcal daily) and the intake of carbohydrates, but meets the "three factors + one" criteria as I mentioned in another post, they will gain weight (this means an increase in base weight).

[Related article] →Three (+one) Factors to Accelerate “Intestinal Starvation”

Of course, weight gain mostly occurs when the person then goes back to the original diet, but in this case, absorption ability itself goes up, meaning that not only body fat, but also blood and muscle mass,etc. increase, resulting in "weight gain."

In short, even though you are eating the same amount of food (calories) as before, you are taking in more energy and nutrients into your body than before, which means you are getting bigger/fatter.
In the words of Gary Taubes, "a room crowded with ten people now has eleven people," and in this case,
it is “intestinal starvation” that has caused it.
  

The bottom line

(1) Since the human body is a mass of chemical reactions and not a "closed system," it does not make sense to compare the total calories actually eaten with the calories expended. In this case, the "law of thermodynamics" does not hold.

(2) If we base it on the calories actually absorbed in the intestines, it should be closer to a "closed system" and be balanced with the calories expended through one’s basal metabolism and activity,etc.

(3) If intestinal starvation is induced and your base weight goes up, you will gain weight even if you are eating the same amount as before, which means that the energy taken into the body has increased. Since the absorption ability itself has gone up, the increase in body weight is related to not only body fat, but also blood and muscle mass,etc.