I would like to share with you an interesting story based on profound research that is also relevant to my theory. I will conclude this post with my thoughts.

 【Related article】The Combination of Thin and Overweight in the Same Poor Group Is Not Contradictory

In Japan as well, this idea is widely accepted, and most experts on television explain that overeating and physical inactivity are the causes of obesity.
  

However, what we have to consider here is that obesity is spreading in the poor layers of society, too.
                   

"Between 1901 and 1905, two anthropologists independently studied the Pima (Native American tribe in Arizona), and both commented on how fat they were, particularly the women.

Through the 1850s, the Pima had been extraordinarily successful hunters and farmers. By the 1870s, the Pima, however, were living through what they called the 'years of famine.' (*snip*)

<About the case of the Pima (Native American tribe in Arizona >

"So why were they fat? Years of starvation are supposed to take weight off, not put it on or leave it on, as the case may be. 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?

Hrdlička also thought that their physical inactivity was the cause of obesity because they were sedentary in comparison with what they used to be. This is what Hrdlička called 'the change from their past active life to the present state of not a little indolence.' But then he couldn't explain why the women were typically the fat ones, even though the women did virtually all the hard labor in the villages—harvesting the crops, grinding the grain, even carrying the heavy burdens.

I want to explain my consideration based on numbers one to three.
First of all, when considering "obesity," isn't it too simplistic to think that obesity has increased since we have become wealthier? 

That is to say, even if someone is said to be wealthy, with regards to food, there are many things in common with groups that live in poverty with a high rate of obesity. As Mr. Taubes says, what is important now is the “quality” of food rather than the “quantity.”

Many should have argued that, “if the Earth is going around the sun, our heads should go around, too.” However, now, it’s common sense that the Earth is going around the sun.

In the same way, many might not believe me when I say, “people can gain weight by intestinal starvation and it is the fundamental cause of being overweight.” However, I believe it’s the truth.

It is said that, “eating too much and not enough exercise are the causes of gaining weight,” but here is an interesting experiment that is related to it.
 

"In the early 1970s, a young researcher at the University of Massachusetts named George Wade set out to study the relationship between sex hormones, weight, and appetite by removing the ovaries from rats (females,obviously) and then monitoring their subsequent weight and behavior.

The effects of the surgery were suitably dramatic: the rats would begin to eat voraciously and quickly become obese.The rat eats too much, the excess calories find their way to the fat tissue, and the animal becomes obese. This would confirm our preconception that overeating is responsible for obesity in humans as well.

＜1970s＞
Words of Bruce Birstrian who conducted a treatment of a low-calorie diet (600kcal/day) to thousands of obese patients at Harvard University of Medicine.

My experience is a little different from the rats’ story, but I want to tell of my experience that I gained weight not because of eating more.

When I was very thin, under forty kilograms, I couldn’t eat a lot since my stomach always felt heavy. Fatty foods and oily foods were the worst. I tried hard to gain weight, but I couldn’t.

One day, I realized that I could gain weight by eating only easy-to-digest foods (mainly carbs and a little meat) and experiencing being hungry for hours. So, I tried to eat light meals for breakfast and lunch, and I tried not to eat vegetables and fat very much until dinner. By doing so, I gradually gained weight. And when I weighed about fifty kilograms, I had more muscle and less discomfort in my stomach. I was able to eat more than before.

    
Those who didn’t know my experience told me, “You’re gaining weight because you’re eating more,” but that wasn’t true.

After my body adjusted to my new eating plan, I gained weight little by little by eating. As I gained weight, I gradually gained more muscle and my appetite increased. As a result, I was able to eat more than before. So, the reality was the other way around.
 

However, could it that individuals who are naturally lean are simply more likely to end up as elite long-distance runners or cyclists? In other words, might their natural leanness cause certain people to be more active, rather than the other way round?

There's actually some evidence for this. In one piece of research, the relationship between physical activity and body fatness in children over a 3-year period was assessed. It was found that the more sedentary children were, the more fat they carried.

I agree with this opinion, but I’d like to add my own opinion. 
As Dr. Briffa said, I think it’s reasonable to think those who are slim aim to be marathon athletes or soccer players, etc. They at least know that they can eat a lot and not get fat. So they will eat whatever they want without hesitation, won’t they?

In other words, by eating balanced foods every meal, intestinal starvation doesn’t happen —by that, I mean their set-point for body weight doesn’t change—and they keep their current weight while getting a little more muscle. 

On the other hand, when people stay at home, spending time relaxing with a book or watching television, or when doing office work or light physical labor, don’t they tend to eat less or lighter meals? 

On the other hand, for the ninety kilogram wrestler, it’s a practice which is relatively easy, since there are only those who weigh less than him. Even if they do the same practice, the level of challenge is different for each wrestler.

Let’s see it again here by using a “delivery center” example. A delivery center is a place where they sort packages and send them out everyday. There are two delivery centers. Center A has a capacity of five hundred packages, and delivery center B has a capacity of eight hundred packages. 

I guess you already know what I want to say. Here again, we have three ladies of different weights eating the same thing. A: 90kg, B: 60kg, C: 45kg.

Let’s say all three had the same hamburger set for lunch.

Here, when we focus on body size, you can say, “A is eating quantitatively less." When we focus on digestive ability, “A is eating qualitatively simpler than C.

“Qualitatively” means that those with a stronger digestive ability can digest the same amount of food faster, even if they are the same body size. For example, it's been said that Caucasians generally have stronger digestive enzymes for protein and fat, compared to many Asian people.

(1) Based on my intestinal starvation theory, people who have a bigger body or stronger digestion eat relatively less or lighter meals compared to thin people. They are more likely to feel hungrier, and depending on what they eat, they are prone to inducing intestinal starvation and gain more weight.

            
(2) Also, assuming that European, American, or African people generally have a stronger digestion for fat and protein compared to many Asian people, they are more likely to gain weight than many Asians, even if everyone eats the same. It’s not that they have particular obesity gene.
                

Many people say that eating too much fat or oil makes you fat, since fat has more than twice as many calories as carbohydrates or proteins per gram. But some research shows that some people can lose weight even though they increase fat or oil in diets.
Which is true?

To make a long story short, I think both are correct. As I have mentioned so many times before in this article, there are two meanings to the phrase “gain weight,” and based on my theory, I can say that eating fat has three sides to it.

He concluded :

• Low-fat diets are ineffective for weight loss.
  
• Dietary fat intakes are not strongly linked to body weight, and some evidence links increased fat intake with lower body weight.
  
• Insulin is the key driver of fat accumulation in the body. Dietary fat does not stimulate insulin secretion directly, and therefore has limited fattening potential.”
  
• Obviously, eating nothing but fat is not to be advised, but some study open up the possibility that a fat-rich diet may actually assist our weight-loss efforts[1].
     

I’m not a specialist or researcher. Therefore, I’d like to avoid mentioning how insulin or other hormones work in the bloodstream. But I believe I can explain why low-fat diets are ineffective for weight loss vs fat-rich diets that may help our weight-loss efforts, based on my theory.
I will explain in the next section. 

Based on my experience, I believe that people who say they gained weight by consuming fat or those who say they lost weight, are both true. However, each only highlights one aspect of the properties of fat. Focusing solely on 'calories' can obscure these different aspects. 

I can say that three different effects can be expected depending on the the subject of intake (who) and/or the way of intake (such as the amount and frequency).

People who have a higher digestive ability for dietary fat, especially those who are dedicated to dieting to keep their weight low or those aiming to shed excess fat to achieve a muscular physique, will get especially fat in a few days if they consume high-calorie foods like sweets, cakes, and deep-fried foods. The fattening effect seems especially acute when eaten with a good amount of carbohydrates or when having only two meals a day. 

　　
With these images, many people reject a revolutionary suggestion of taking fat/oil in order to get slim, and that’s what makes this theory hard to accept.
              

In any case, fat digestion is more complex than other nutrients and tends to inhibit intestinal starvation.

For example, if a thin person wants to gain weight, eating a lot of fat/oil at meals will hinder gaining weight. Have you ever wondered, “why was he/she not getting fat despite the fact that they were eating high calorie foods, such as cakes, cookies, deep-fried foods, or fatty foods?”

In fact, a low-fat, easily digestible diet is more likely to make you gain weight in terms of increasing your set-point weight itself.
       

As Dr. Briffa whom I’ve mentioned above said, I also believe that "in a low-carb diet, increased fat intake is linked to lower body weight” is in a way correct, as though this doesn’t apply to everyone. 

It is generally believed that the reason is that fat, unlike carbohydrates, does not stimulate insulin secretion, but I will avoid mentioning that for now. Other than that, here is what I would like to add and explain based on my theory.

The time it takes for fat to be completely digested can be six to eight hours, depending on the amount of food eaten and how we combine different foods. Therefore, by consuming fat/oil every four to five hours, undigested food will remain in the stomach and the large part of the intestines for most of the day, which lead to decreased feeling of hunger and, in turn, reduced absorption ability (rate and amount).

As seen in low-carb diets, by decreasing carbohydrate intake to an extent and increasing the intake of fats, proteins, nuts, and vegetables, etc., dense nutrients are delivered to the intestines, which takes even longer to digest. If you continue with this eating habit, I believe it maximizes the dieting effect. 

[Related article]
The Dilution Effect/ Pushing Out Effect of Carbohydrates
      

(1) Just because fat has nine kilo calories per gram, does not mean that dietary fat always makes people fat.

For those who have a higher digestive ability for dietary fat, especially those who normally keep their weight lower to lose weight, eating fatty food can be a cause of weight gain, but depending on the subject of intake (who) and/or how you eat it (how much, how often), fat can have a deterrent effect to further weight gain or diet effect.

(2)Fat takes longer to digest than other nutrients, so if you frequently eat fat, undigested food tends to remain in the intestines. This makes intestinal starvation less likely to occur, which tends to deter further weight gain in the sense that one’s set-point weight doesn’t change.

(3)A diet low in carbohydrates but high in protein and fat may have a dieting effect. It is generally believed that the main reason is that fat, unlike carbohydrates, does not stimulate insulin secretion.

My theory, I would add, is that ingesting fats every four to five hours will leave undigested food in the wide range of intestines, which will lead to reducing feeling of hunger and, in turn, decreased absorption ability. Continuation of this condition could have a weight-loss effect.
         

It is said that exercising and food restriction is necessary for losing weight. However, we rarely meet those who succeeded in dieting using such a method.

Japanese wrestler Bull Nakano (below) has repeatedly dieted and rebounded, but after having knee problems, it was imperative that she lose weight, so she had a gastrectomy to remove part of her stomach.
She said that “cutting the amount of foods and exercising didn’t make her thinner.”

In this article, I would like to introduce how conventional calorie-based diets are ineffective, based on two books: "Escape the Diet Trap" and "Why Do We Get Fat.”
Please note that most of these are quotations.

"Limiting the studies to those where individuals were monitored for at least two years after the start of their efforts to lose weight allows us to assess the long-term success of these approaches. Many of us will know what it is to get a short-term win from eating less and exercising more but it's the long game we're interested in here.

 "Prescribing low-calorie diets for obese and overweight patients, according to a 2007 review from Tufts University, leads, at best, to “modest weight losses” that are “transient” – that is, temporary. Typically, nine or ten pounds are lost in the first six months. After a year, much of what was lost has been regained.

Together they enrolled more than eight hundred overweight and obese subjects and then randomly assigned them to eat one of four diets. These diets were marginally different in nutrient composition (proportions of protein, fat, and carbohydrates), but all were substantially the same in that the subjects were supposed to undereat by 750 calories a day, a significant amount.