Why Are Sumo Wrestlers So Fat?; Six Reasons They’ve Adapted to the Gut Starvation Mechanism


  1. The same mechanism as people who rebound after dieting
  2. The six reasons that I believe it is a starvation mechanism
    The bottom line


Have you ever seen a sumo wrestler right in front of you? When I was working as a waiter at a hotel several years ago, there was a pep rally for sumo wrestlers, and I was able to see them up close.

Also, at the 2017 Osaka tournament in Japan, I observed the morning practice of a team and was allowed to sample their breakfast called "chanko."

meal called chanko

I had a sample of "chanko."

sumo wrestler

I got the impression that they are big-boned, with steel-like muscles, and a lot of body fat on top of that.  

Their average body fat percentage is said to be around thirty percent or more, but there are some wrestlers in the twenty percent range, not that different from the average person. They are like a mass of muscles. 

It is generally believed in Japan that wrestlers will gain weight because they eat a lot and sleep well including taking naps, but I can explain that they have successfully adopted the mechanism of intestinal starvation.

1. The same mechanism as people who rebound after dieting

In Japan, the image of sumo wrestlers in particular may lead to the image that "eating more makes you fat," but I would like to explain that this is the same mechanism as "those who end up rebounding after dieting and gain more weight than before" or "those who gradually gain weight by skipping breakfast or having a late dinner.”

First of all, I'm going to illustrate how both of them gain weight in the figure below. 

■The concept of a person who gains more weight after dieting than before

gaining more weight after dieting

Proceed in order: (1) → (2) → (3)

(1) You will lose a little weight through caloric restriction or exercising, etc.

(2) When you eat less (especially with an unbalanced diet), and you feel hungry for an extended period of time, you tend to starve your gut, and your base weight may go up without you realizing it. 

(3) Later, when you start eating as you did before dieting, your weight will be higher than before.

■The concept of sumo wrestlers gaining weight

The image of wrestlers gaining weight

Proceed in order: (1) → (2) 

(1)By their traditional unique diet and hard practice, intestinal starvation can be induced.

(2)First, their base weight goes up little by little, and then they gain weight by eating.

If you are a dieter, there is a time lag, but in the case of wrestlers, they eat good amounts of food every day, so it happens almost simultaneously.

Although they appear to eat a lot and are gaining weight, if intestinal starvation is not induced, their weight should not increase as much as expected.

2. The six reasons that I believe it is a starvation mechanism

When you see big eaters in a food eating competition, some may ask, "Why don't they get fat even though they eat so much?” But, from my theory, it is not at all surprising.

It’s not that they have a special "non-fattening constitution," but that anyone who eats like that from morning to night is less likely to gain weight (although I wonder why they can eat so much food at once).

Please understand that the way of eating of a sumo wrestler is a far cry from that of an eating competitor.

■An explanation of why the way of eating and exercising of sumo wrestlers can easily induce intestinal starvation. (1) - (6) 

(1)A wrestler must weigh at least sixty-seven kilograms to be admitted. People who are overweight or muscular from the beginning tend to have stronger stomachs, and are thought to have a relatively high digestive rate. Such people are more likely to induce gut starvation than thin people.

a chanko dish

(2) The basic diet for sumo wrestlers is called "chanko," which consists of vegetables, chicken, fish, tofu, and other ingredients slowly simmered in soy sauce. It is relatively low in fat and easy to digest.

(3) Sumo wrestlers generally eat a good amount of rice. By eating a lot of rice and soup, the stomach expands (the balloon effect), which leads to creating the dilution effect and push-out effect of food in the stomach.

[Related article]

The Dilution Effect/ Pushing Out Effect of Carbohydrates

(4)They traditionally eat two meals a day: the first meal is around eleven a.m. after morning practice, and dinner is around six p.m.
Since they practice from the early morning without breakfast, if dinner is finished at seven p.m., it means that they do not eat for about fifteen to sixteen hours until the next meal. It make sense to do intense morning training on an empty stomach to gain weight.

Of course, there are some wrestlers who try to eat snacks or supplements late at night in order to take in more calories, but my idea is that it makes easier to gain weight when they don't eat.

morning practice of sumo wrestler

(5)Strength training is a force for gaining strength, and it ultimately works in the direction of weight gain; eating two meals a day and exercising intensely will make sumo wrestlers gain more weight.

(6)The main simmered food in a pot is eaten first by the top-ranked wrestlers, and later by the lower-ranked wrestlers and new trainees.

The last people have to eat a big ball of rice and leftovers, which consists of only a little meat and most of the soup.
it is said that this kind of meal tends to make sumo wrestlers gain more weight.

The bottom line

(1)Sumo wrestlers are famous for being big and fat, but they do not gain weight because their daily caloric intake exceeds their daily caloric expenditure.
Their traditional diet and exercise makes sense in terms of weight gain in that it facilitates the creation of intestinal starvation.

(2)Intestinal starvation is more likely to be induced when a person who has a big body from the start eats relatively easily digestible foods with lots of carbohydrates (rice) and two meals a day.

(3)The mechanism by which wrestlers gain weight is the same as that of "people who diet and gain more weight than before due to the rebound effect.”
In the case of sumo wrestlers, since they eat a lot every day, this happens almost simultaneously, and they appear to eat a lot and gain weight.


People Who Usually Eat Less and Occasionally Splurge Gradually Gain Weight


  1. People who gained weight during the Covid self-quarantine period 
  2. A wrong strategy is to skip a meal today because you ate too much yesterday
  3. Daily actions taken by people who are gradually gaining weight
The bottom line

1. People who gained weight during the Covid self-quarantine period 

According to a survey, more than fifty percent of Japanese people put on some weight during the period of staying at home by government order to prevent the spread of the coronavirus.

Stay home

I saw a woman on television. She is a dance instructor and gained more than ten kilograms during this period.

Also, a friend of mine who owns a Japanese restaurant and works as a chef, gained almost five kilograms.

He usually skipped breakfast and did not eat much dinner after his restaurant closed (around 11:00 p.m.), but during this period of self-quarantine, he stayed at home watching television and eating three times a day.

I think two classic examples of "eating a lot or stopping exercising makes you fat" fit here.
Normally, these people were under the strain of their jobs, moving all day long, eating in moderation, and paying attention to caloric intake.
If that tension is gone and they simply exercise less and eat more, they will naturally gain weight.

base weight

However, this is the same pattern as rebounding, which means their weight go back to their base weight (Figure-B).

When these people return to their regular jobs, they have to reduce their food portions and caloric intake in order to go back to the weight they’d temporarily gained, even though they have to move around.

2. A wrong strategy is to skip a meal today because you ate too much yesterday

Sometimes I hear people say, "I ate too much at the all-you-can-eat buffet yesterday and gained three kilograms in one night.” They may have simply gained body fat or the weight of the food in their gut may also be a factor.

But It is a big mistake to say, "Okay, let's skip today's lunch." 

Food ingested yesterday has already passed through the gastrointestinal tract and may be excreted in the form of a stool, but if you eat less today and put up with hunger over many hours, intestinal starvation may be induced, and your base weight may increase slightly.

So, it does not make sense to offset the extra calories you ate yesterday by eating less today.

3. Daily actions taken by people who are gradually gaining weight

With the recent gourmet food boom, many delicious foods are introduced on television and social media, while many people are worried about gaining weight and are trying to eat less.

a feast

Many of them usually restrain themselves as much as possible on the foods they want to eat, cutting back on calorie-dense foods such as sweets or fried foods.

Then, they splurge once in a while and eat their favorite foods as a reward.

In the end, they regret the weight they have temporarily gained and say, "Let's start dieting again tomorrow," and engage in a calorie-restricted diet.

I have no doubt whatsoever these diets are rarely successful. Rather, they tend to gain weight little by little. Eating on and off, or eating unevenly, is the first step toward becoming overweight.

If you skip meals or eat light meals (e.g. hamburgers and coffee) to reduce calorie and carbohydrate intake, you will deal with hunger for a longer period of time.

Even if you lose a little weight temporarily, the lack of fats, oils, dairy products, and fibrous vegetables can lead to intestinal starvation and an increase in your base weight over the long haul.

Unknowingly, your base weight may go up, and one day, when you eat like you used to, you may find that you have reached your highest weight ever. And it will be harder to lose weight than before.

The gastrointestinal tract starts by eating breakfast, and the food we eat is delivered to the rectum in around twenty hours or more (it differs from person to person).

Therefore, it is a mistake to say, "I ate too much yesterday, so I will skip lunch today," or "I ate a lot of fibrous vegetables yesterday, so I don't need them today.”

It is also a mistake to say, "I will eat enough vegetables and nutritious foods at dinner, so I will go with a light and frugal breakfast and lunch." 

The first step in becoming leaner is to eat three well-balanced meals religiously every day. 
Even if you want to reduce total caloric and carbohydrate intake, be sure to consume fiber-rich vegetables, seaweed, dairy products, proteins such as meat and fish, and oils every meal.

The bottom line

(1) Some people claim to have gained a few kilos during the Covid self-quarantine period, but I believe most cases can be explained by a return to one’s base weight as well as a rebound effect.

(2) The idea of adjusting for yesterday's excess calories by eating fewer calories today is a mistake when it comes to maintaining a stable weight in the long run.

(3) People who usually eat less and hold back on the foods they want to eat for dieting, and occasionally splurge on treats, are more likely to gain weight over the long haul.

Irregular eating, where a person eats on and off, can cause intestinal starvation when a person is dealing with hunger over many hours, unknowingly increasing their base weight.

(4) Since the gastrointestinal tract basically begins with breakfast and the food we eat reaches the rectum in around twenty hours or so, it is important to eat three well-balanced meals every day if you do not want to gain weight.


Does Obesity Run in the Family or Is It Due to the Living Environment?


  1. What was the relationship of weight between adoptees and "adoptive parents"?
  2. What was the weight of the twins raised apart?
  3. What do we consider a "change in environment?" My thoughts
  4. Will the shape of your body from childhood continue?
    The bottom line

Is obesity inherited from parents?

Let us recall our classmates in elementary school. To some extent, we can imagine, if not one hundred percent, that if the parents are thin, their children are often thin, and if the parents are fat, their children are often fat.

The question here is whether this is due to genetics or due to the living environment. Here is one such study I’d like to introduce.

a family

1. What was the relationship of weight between adoptees and adoptive parents?

"Obese children often have obese siblings. Obese children become obese adults. Obese adults go on to have obese children. Childhood obesity is associated with a 200 percent to 400 percent increased risk of adult obesity. This is an undeniable fact. (*snip*)

Families share genetic characteristics that may lead to obesity. However, obesity has become rampant only since the 1970s. Our genes could not have changed within such a short time. Genetics can explain much of the inter-individual risk of obesity, but not why entire populations become obese.

Nonetheless, families live in the same environment, eat similar foods at similar times and have similar attitudes. Families often share cars, live in the same physical space and will be exposed to the same chemicals that may cause obesity–so-called chemical obesogens.
For these reasons, many consider the current environment the major cause of obesity.

environmental factors for obesity

Conventional calorie-based theories of obesity place the blame squarely on this “toxic" environment that encourages eating and discourages physical exertion. Dietary and lifestyle habits have changed considerably since the 1970s (e.g., cars, TV games, computers, fast food, high-calorie foods, sugar, etc.).

Therefore, most modern theories of obesity discount the importance of genetic factors, believing instead that consumption of excess calories leads to obesity. Eating and moving are voluntary behaviors, after all, with little genetic input. So-exactly how much of a role does genetics play in human obesity?

The classic method for determining the relative impact of genetic versus environmental factors is to study adoptive families, thereby removing genetics from the equation.(*snip*)

Dr. Albert J. Stunkard performed some of the classic genetic studies of obesity. Data about biological parents is often incomplete, confidential and not easily accessible by researchers. Fortunately, Denmark has maintained a relatively complete registry of adoptions, with information on both sets of parents.

adoptive families

Studying a sample of 540 Danish adult adoptees, Dr. Stunkard compared them to both their adoptive and biological parents. 

If environmental factors were most important, then adoptees should resemble their adoptive parents. If genetic factors were most important, the adoptees should resemble their biological parents.

No relationship whatsoever was discovered between the weight of the adoptive parents and the adoptees.(*snip*)

Comparing adoptees to their biological parents yielded a considerably different result. Here there was a strong, consistent correlation between their weights.

The biological parents had very little or nothing to do with raising these children, or teaching them nutritional values or attitudes toward exercise. Yet the tendency toward obesity followed them like ducklings. When you took a child away from obese parents and placed them into a "thin" household, the child still became obese.(*snip*)

This finding was a considerable shock. Standard calorie-based theories blame environmental factors and human behaviors for obesity. Environmental cues such as dietary habits, fast food, junk food, candy intake, lack of exercise, number of cars, and lack of playgrounds and organized sports are believed crucial in the development of obesity. But they play virtually no role.

2. What was the weight of the twins raised apart?

Studying identical twins raised apart is another classic strategy to distinguish environmental and genetic factors. Identical twins share identical genetic material, and fraternal twins share 25 percent of their genes. 

In 1991, Dr. Stunkard examined sets of fraternal and identical twins in both conditions of being reared apart and reared together. Comparison of their weights would determine the effect of the different environments.

The results sent a shockwave through the obesity-research community. Approximately 70 percent of the variance in obesity is familial.(*snip*)

a dentical twin

However, it is immediately clear that inheritance cannot be the sole factor leading to the obesity epidemic.

The incidence of obesity has been relatively stable through the decades. Most of the obesity epidemic materialized within a single generation. Our genes have not changed in that time span.
How can we explain this seeming contradiction?" 

(The Obesity Code, Dr. Jason Fung, 2016, Pages 21-24) 

3. What do we consider a "change in environment?" My thoughts

I think this is a very interesting study because it compared data from biological parents and adoptive parents.

However, can we assert from the results of this one alone that the influence of genetics was much greater and environmental factors were much less significant?

I believe, as Dr. Fung mentions, the rapid increase in obesity in recent years (since about 1970) has much to do with changes in our living environment (what we eat, irregular lifestyle,etc.),not the genes.

Even those who were slim in their youth may gain five or ten kilos in a short period of time at a certain age, triggered by something (living alone, marriage, parenting, stress from work, etc.). Some people put on weight every time they try dieting to lose weight.

In other words, many of us, in our hearts, have probably noticed that changes in eating habits (not the caloric intake) or our living environment can change our body shape.

■What is the "change in environment" that causes a change in weight here?

The study considers a child living with adoptive parents or twins raised separately to be a "change in living environment," but I think there is a problem with this study.

If a family can afford to take in a child as adoptive parents, don't they have some money to spare and feed their adoptee a somewhat balanced diet three times a day?
Although what they eat and caloric intake may differ from family to family, those changes don’t necessarily lead to a change in what I call their base weight. Just because the adoptive parents are thin does not mean that adoptees will become thin even if they eat the same diet.

For example, there is a Japanese comedian who is very fat (she always laughs off her being fat). She didn't know breakfast existed until she was thirteen years old (because her mother never made it at all), but what if such a family were her adoptive parents?
If a child is adopted into such an extreme family, it may well affect their weight in the long run,
but if they are in a family that feeds them a standard diet three times a day, It can’t be said that it is a "change in environment."

On the contrary, a fundamental change in weight and body shape occurs when one’s base weight itself goes up due to intestinal starvation, which requires three (+one) factors to be induced.

[Related article] 

Three (+one) Factors to Accelerate “Intestinal Starvation”

In Japan in the past few decades, our traditional habits have been declining. Instead, our diet has become more westernized and our ways of working have become more diverse.
When some of these conditions such as not eating breakfast or lunch, eating late at night, fast food, not eating vegetables, carbohydrate-dense food, etc. are combined, intestinal starvation may be induced and lead to an increase in base weight.

This is the "environmental factors and human behaviors for recent obesity epidemic,” I want to say, and I believe that environmental factors has more influence than genetics. (Of course, genetic factors cannot be ignored).

4. Will the shape of your body from childhood continue?

childhood obesity

One thing to note here is that the body shape in childhood (say, around three to five years old) tends to continue into adulthood.

When I think back to my classmates in first and second grade, the girls and boys who were fat (although they were not big eaters) often have a similar body shape even decades later.

From my theory, that means that their base weight has not changed, and in this study, if there are no environmental factors that cause changes in their base weight, then wouldn't the body shape from childhood basically continue?

But, I’m simply wondering what the childhood body shape is due to? Whether it is genetic factors or the way food is fed during childhood-including weaning-is a question that remains unanswered.

The bottom line

(1) In a study regarding adoptive families and examining how genetic and environmental factors influence being overweight, no correlation was found between the weight of adoptive parents and that of their adoptees.
On the other hand, when the adoptees were compared to their biological parents, there was a consistent correlation between the weight of both.

A study of twins raised separately also concluded that "genetic influences are far more significant.”

(2) Many researchers had previously blamed "environmental factors and individual behavior” for the recent obesity epidemic, but this study concluded that genetics had far more impact than environmental factors.

However, I find this study problematic. The fact of children living with adoptive parents or twins raised separately is not necessary an environmental factor that causes changes in weight.

(3) Regarding the similarity in body shape between biological parents and their children, of course, I do not think we can ignore the genetic factor, but the recent obesity epidemic can be explained by my intestinal starvation theory.

A major change in weight and body shape occurs when one’s base weight value goes up, which is induced by intestinal starvation. It requires (three + one) factors for that to occur.

(4) If there is no significant change in base weight, I think the body shape from childhood is expected to continue. However, I 'm uncertain what determines childhood body shape, whether it is heredity or the way food is prepared during childhood, including weaning.


Why Does the Body Perceive That It Is More Starved than in the Past?


  1. How has our Japanese diet changed over the past fifty years?
  2. The Pima tribe who gained weight under rations, not prosperity 
  3. The newer the diet in history, the less fit the body is
<End Note>

1.How has our Japanese diet changed over the past fifty years?

I was born in 1970, about fifty years ago. That was when twenty-five years had passed since the end of the World WarⅡ, and Japan was in the midst of its rapid economic growth.

In retrospect, I feel that the food scene was quite different from what it is today. My parents were farmers in the country side of Osaka, growing rice and mushrooms. We also had about twenty chickens to get fresh eggs.

On the dining table in the morning, there was usually rice, miso soup, pickles, traditional stewed vegetables, and half-dried fish. I remember the family eating together.
Of course, we sometimes ate bread, but my father did physical labor, so rice was an essential part of breakfast.

Balanced breakfast

(Typical Japanese breakfast we used to have)

■The 1970s, when the dining scene changed dramatically

I think it was after 1970 that our dining landscape slowly changed. I had not been taken to restaurants much when I was a kid, but fast food restaurants and other restaurant chains opened one after another in all corners of Japan, and many people began to eat Western food.

McDonald's (since 1971), Kentucky Fried Chicken (since 1970) and family restaurants called Skylark (since 1970) were the most famous among them. In 1974, the first convenience stores (called Seven-Eleven) opened in Tokyo, followed by a rapid increase throughout the country. Instant foods such as cup noodles and frozen foods also increased rapidly, reflecting busy social conditions.

fast food

Even in the 1970s, school lunches already had bread as their side dish rather than rice (apparently at the behest of GHQ, which ruled after the war), and those of us who had grown accustomed to such a diet began to prefer bread, noodles, and other wheat products even as adults.

Along with this, we liked to eat meat and processed foods rather than fish with bones. We began to prefer soft foods to fibrous and hard foods, and the traditional vegetable stews that had been commonly eaten became less and less common.

Our lifestyles also changed dramatically. More and more people began to work at desks rather than at physical jobs. Nighttime lifestyles became the norm, and more people didn't even eat breakfast.

It was probably around this time that obesity began to increase in Japan. Nowadays, it is not unusual to see women over one hundred-kilograms on the streets.

Obesity rate in Japan

(Percentage of adults with a BMI of 25 or higher: In both men and women, it has been increasing since 1980 

One might think that increased caloric intake was the cause of being overweight.

However, on a caloric basis, the average daily caloric intake of the population in 1970 was twenty-two-hundred kcal, yet in 2010 it had decreased to eighteen-hundred-fifty kcal. [1] 

(Reference [1]: Yasuo Kagawa, "Clock Gene Diet," 2012, P.15)
light breakfast and lunch

(an inverted triangle-type diet)

To explain this in my theory, the modern diet is often low in fiber and heavy on easily digestible carbohydrates and meat, which can, in turn, induce intestinal starvation based on how we combine the foods.

In particular, the following eating patterns can easily create a state in which all food is digested in the gut.

(1) Two meals a day, leaning toward carbohydrates and easily digestible protein.

(2) A simple, light meal for breakfast and lunch, and added fibrous vegetables and nutritional foods at dinner. (What I call an inverted triangle-type diet).

2. The Pima tribe who gained weight under rations, not prosperity

As an example of how obesity has increased as old traditional eating habits have declined and became westernized, I would like to cite a Native American tribe known as the Pima, although the situation is slightly different.
This is the second time I quote from Mr. Taubes "Why We Get Fat," but this part is very important and may be the key to solving the problems of obesity, diabetes, and other diseases.

"Consider a Native American tribe in Arizona known as the Pima. Today the Pima may have the highest incidence of obesity and diabetes in the United States. Their plight is often evoked as an example of what happens when a traditional culture runs afoul of the toxic environment of modern America. (*snip*)

Between 1901 and 1905, two anthropologists(Russell and Hrdlička) independently studied the Pima, and both commented on how fat they were, particularly the women. (*snip)

Through the 1850s, the Pima had been extraordinarily successful hunters and farmers. 

Pima tribe

By the 1870s, the Pima were living through what they called the “years of famine.”(*snip*) The tribe was still raising what crops it could but was now relying on government rations for day-to-day sustenance.(*snip*)

What makes this observation so remarkable is that the Pima, at the time, had just gone from being among the most affluent Native American tribes to among the poorest.
Whatever made the Pima fat, prosperity and rising incomes had nothing to do with it; rather, the opposite seemed to be the case.

And if the government rations were simply excessive, making the famines a thing of the past, then why would the Pima get fat on the abundant rations and not on the abundant food they'd had prior to the famines? Perhaps the answer lies in the type of food being consumed, a question of quality rather than quantity.(*snip*)

So maybe the culprit was the type of food. The Pima were already eating everything “that enters into the dietary of the white man,” as Hrdlička said. This might have been key. 

The Pima diet in 1900 had characteristics very similar to the diets many of us are eating a century later, but not in quantity, in quality."

(Gary Taubes, Why We Get Fat, 2011, P. 19-23)

[Related article] Wealthy Ones Get Fat? Poor Ones Get Fat?

In terms of food, I believe that Japanese people in 1970 were eating a lot of different kinds of food than today. There were no convenience stores, and the diet was based on mom's home cooking, with a variety of seasonal vegetables and fish.

In contrast, the modern diet is based on easily digestible carbohydrates and meat, and the variety of food ingredients we eat seems to have decreased dramatically. Many people are normally worried about gaining weight and are dieting, and then they occasionally splurge and eat high-calorie food as a reward. The situation is different, but if we focus on the inside of the intestines, I can say that it is the same as what happened to the Pima population.

3. The newer the diet in history, the less fit the body is

"The idea is that the longer a particular type of food has been part of the human diet, the more beneficial and less harmful it probably is— the better adapted we become to that food.

And if some food is new to human diets, or new in large quantities, it's likely that we haven't yet had time to adapt, and so it's doing us harm. (*snip*)

Wild boar meat

The obvious question is, what are the “conditions to which presumably we are genetically adapted”? As it turns out, what Donaldson assumed in 1919 is still the conventional wisdom today: our genes were effectively shaped by the two and a half million years during which our ancestors lived as hunters and gatherers prior to the introduction of agriculture twelve thousand years ago."

(Gary Taubes, Why We Get Fat, 2011, P. 163-164)

I believe what the author tried to get across was that the modern diet of allowing large amounts of carbohydrates is not genetically compatible with our bodies, and that eating meat and its fat may be more compatible and less harmful to us on a genetic level.

I will quote this passage above to explain my intestinal starvation mechanism.

Suppose (and it makes more sense) that God created a genetic blueprint for people to "store body fat" in case they could not find food. 

The food we used to eat

If the state of "no food" (starvation) was recognized when all food was digested in the entire intestinal track, then during the hunting-and-gathering age and farming age when people ate wild boar meat, nuts, root vegetables, and unrefined grains, their intestines would not have been in a state of complete starvation even if they couldn’t eat anything for a whole day (because of the long intestines).

In contrast, a modern diet high in refined wheat/rice, starch, easily digestible protein, and processed foods can lead to intestinal starvation even in just half a day. I believe it is the entire intestines (or it may be the small intestine only) that makes all the decisions, and it goes to show that inside the gut, many of us are  starving more today than in the past.

End Note

People sometimes say, "Japanese food culture is healthy by world standards," but I believe this to be a relic of the past until around the year 2010 at the latest. Now, I feel that traditional Japanese food culture is dying in the average household.

Children who grew up eating fast food are now in their fifties and sixties, and their children are now in their thirties. Thus, in about fifty to sixty years (about two generations), the opportunity to eat traditional foods will have faded away, and the food culture will change greatly.

And, with the shift in diet, it seems like that diseases such as diabetes, kidney disease, heart disease, cancer, and stroke, which were once not as common, are on the rise, just as they are in the Western countries.


Can Thermodynamics Explain Why We Gain Weight?


  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) Experts believe that the cause of obesity is the "imbalance between caloric intake and consumption" based on the "law of energy conservation" (the first law of thermodynamics).

(2)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.

(3) 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.

(4) 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.