— Topics —
Basal metabolism


It’s the ”Absorption Ability" Rather Than the Caloric Intake that Matters


  1. Is there any meaning in calculating the daily caloric intake?
  2. Absorption ability differs from person to person
  3. Is a one-calorie intake still one calorie in the body?
  4. ”Being slim due to a high metabolism” is unnatural

1. Is there any meaning in calculating the daily caloric intake?

Is there any meaning in strictly calculating the daily caloric intake to discuss how much weight you can lose/gain? We can’t see how many calories we burn. Similarly, we can never really see how many calories we take in because nutrition is absorbed in the intestines.

Burnd calories and absorbed one

However, many people try to count calories in foods they ate and compare them with the recommended daily caloric intake (using a calorie calculator, etc.). I think what is important is the absorbed amount only.

(Though it might be a theory that is difficult to understand for those with average weight, I believe those with too much or too little weight will understand.)

I think trying to compare everything based on the daily caloric intake is causing various distortions and contradictions. There are those who don’t eat much but are overweights, or those who eat much but are slim, and never gain weight.
It is true that some people who are overweight often eat a lot, but it’s because :

(1) their body is big
(2) their stomach and intestines are large and strong compared to thin people
(3) they often tolerate being hungry for a long time, so they end up eating a lot or perhaps too much.

2. Absorption ability differs from person to person

As each of us have a different ability to exercise, memorize, or communicate, our ability to digest and absorb food also differs from person to person.

In Japan, there are old sayings such as, “You have a body that gets fat even by drinking water,” “A big eater who stays thin,” “Your body is inefficient, since you never gain weight even if you eat a lot,” or “My body is too efficient ーI don’t eat very much, but I get fat easily.”

I I believe all these sayings represent “absorption capability,” explained here.

Also, I’m not sure what percentage of you would agree. However, I want to say it clearly that the fundamental difference between obese people and thin people is based on the absorption capability of each person, not an amount of food they consumed or a good/bad metabolism.

3. Is a one-calorie intake still one calorie in the body?

For example, it is known that the calcium from small fish or the iron from vegetables is difficult to absorb, depending on the person. However, in terms of calories derived from those foods, many people simply total the number of calories they consumed for the day.

I think it’s strange. Is the intake of one calorie still one calorie in the body? Those who say, “It’s one calorie in the body” use “the first law of thermodynamics” as their basis for such an assumption.

"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’. Applying the first law of thermodynamics essentially dismisses any notion that different forms of calorie consumed by an individual can have different effects on weight. In summary: ‘a calorie is a calorie.

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? 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."

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

I have a reason why I wanted to write such an article. I actually felt I couldn’t absorb enough nutrition when I was extremely thin—around thirty something kilograms. And I actually sensed that my intestines were trying to work really hard to compensate after I finished lifting weights.

Back then, I couldn’t gain weight no matter what I ate. Though it was certainly pathological, I thought it was a problem of how much I could absorb. And although it was only once, I gained more than five kilograms in a short period of time (about three days). I was able to sense at that very moment that my body was producing more blood and that I was gaining weight (muscle, too) . After that, when my weight increased to about fifty kilograms, I was able to stay at that weight, even though I didn’t eat as much as I did before. By this, I mean my base weight increased.

4. ”Being slim due to a high metabolism” is unnatural

In Japan, it is often said that those who eat a lot but are slim keep their weight since, “their  metabolism is high” or since, “their body can break down body fat easily,” etc.

However, if body fat is saved as preparation for starvation (since we never know when we can eat until the next meal), will the body break down or metabolize the precious energy source in vain?
 If everyone eats the same and absorbs food in the same way, and those who are thin are using extra energy by having a high metabolic rate, isn’t that unnatural?

It’s often said that gaining muscle will raise the metabolism, but isn’t that because we are shown figures such as a fit model as seen in advertisements?
But I actually think that those who are thin have less muscle and those who are overweight have more muscle under their body fat.

If that’s the case, it will lead us to believe that those who are overweight with much muscle easily or are more likely to lose weight, and those who are thin with less muscle easily or are more likely to gain weight, which is contradictory. This isn’t a good thing for specialists who are just trying to justify themselves such as doctors, nutritionists, etc. to explain why people get fat.


Those Who Are Overweight Had a Higher Basal Metabolism

It is generally accepted (in Japan) that if you build muscle through exercise and increase your basal metabolism, you will be less likely to gain weight.

This is because the calories expended by basal metabolism account for sixty to seventy percent of the total caloric expenditure in a day. (Note: Daily caloric expenditure varies depending on the intensity of the work.)

I'm very thin, so I was skeptical about this, but several years ago there was a program on NHK (Japan's national broadcaster, more reliable than commercial broadcasters) that was helpful!

muscular vs chubby
【Tameshite Gatten(It means “try and get it.”) – I lost weight so easily -】(2011)

When the basal metabolism of the team A (slim and muscular) and the team B (chubby:heavier than A) were examined by a research institute that can precisely measure the basal metabolism, it found that team B had a higher basal metabolism.

In fact, the brain and internal organs (heart and liver, etc.) account for the largest portion of basal metabolism, while muscles account for only twenty percent.

If you want to expend calories of fifty grams of rice (about eighty kcal), the amount of muscle you need is equivalent to about two-point-eight kilograms of meat. 

It seems that you need a lot of muscle in order to lose weight, but this would make you muscle-bound.

In the first place, basal metabolism is the energy expenditure when “you are at rest," so it doesn't seem to have much to do with building muscle.

♦To begin with, if you look up basal metabolism, the general method of calculation is "[basal metabolic standard] x [body weight]" (from wikipedia).

(Basal metabolic standard value)

♦The other method of calculation is called HBE (Harris-Benedict Equation).
[Basal metabolism] (kcal/day)= 66.473+13.7516 [w]+5.0033 [h]-6.7550 [a]
w=weight (kg), h=high (cm), a=age

As you can see from both of these formulas, if you are the same age,
your basal metabolism will be higher if you are heavier (fatter). It's only natural, since their bodies are that much bigger, they must use more energy.

Of course, if you gain more muscle, you may be able to slightly increase these baseline values, but there is not enough evidence to say that you are thin/lean because your basal metabolism is high.

"Since losing weight reduces total energy expenditure, many obese people assume that they have a slow metabolism, but the opposite has proved to be true. Lean subjects had a mean total energy expenditure of 2404 calories, while the obese had a mean total energy expenditure of 3244 calories, despite spending less time exercising.

The obese body was not trying to gain weight. It was trying to lose it by burning off the excess energy. So then, why are the obese... obese?"

(The Obesity Code, Jason Fung, 2016, Page 62)