3 perspectives regarding dietary fat


1.Fat not necessarily means getting fat
2.The reason eating fat makes you slim

   (1) Long-term energy acquired through eating fats
   (2) Deterrent effect of becoming obese
   (3) Diet effect

1.Fat not necessarily means getting fat

Many people say “eating too much fat is the cause of gaining weight” as if it’s common knowledge. There lies the belief that “it's  the calories that makes us obese” and therefore, fat with 9kcal per gram which is more than twice of carbohydrates and proteins (4kcal per gram) is said to makes us easily obese.

However, there are specialists who disagree to this belief such as John Briffa, a British doctor and the author of “Escape the Diet Trap” and Makoto Natsui, a Japanese doctor and the author of “Carbohydrates Will Ruin a Human”.

Dr. Natsui says from his own experience of a carbohydrate restriction diet that “no matter how many calories I take from fat, it doesn't make me fat. I was able to get slim without standing starvation and with a good health condition.”

John Briffa observed in the relative experiment doing various diets, that a low-fat diet has no effect on becoming slim and that a rich-fat diet is more effective to getting slim, while taking hormone secretion, etc. into account.

2.The reason eating fat makes you slim

Based on my experience, both those who gained weight with fat or those who got slim with fat are both true, but these are because they are just different aspects of fat’s own nature. We can’t observe this same result if we just focus on “calories”.

Fat can be categorized into 3 groups which is based on the subject of intake (who) and the way of intake (how many, how often).

(1)Long-term energy acquired through eating fats

Though fat is high in calorie with 9kcal per gram, it takes longer to digest compared to carbohydrates or proteins so:

  •  Foods high in fat helps keep a sense of being full.
  •  Fats won’t increase blood sugar level.
  •  Fats sustain energy for a long time.


Within the Base Weight of such a person, if you ate many calories from fat, you should gain weight naturally.

【Related article】

2 meanings of the phrase "gaining weight"

It’s a common belief by many people that:

  • high calorie sweets or butter make us fat.
  • meals using oil to fry or sauté will make us fat.

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

(2)deterrent effect of becoming obese

In the case where the “Base Weight” itself increases, it will work as rather (*) a deterrent force. (* for those who have a higher digestive ability for fat, may not experience a deterrent force)

For example, if a thin person wants to gain weight, excessive fat will be a hindering force to gaining weight. Have you ever wondered, “why was he/she not getting fat despite the fact that he/she was eating high calorie foods, such as cake, fried foods and meat?” Actually, less-fatty foods are easier to gain weight.

(Japanese Sumo wrestlers)

▽In Japan, Sumo wrestlers (a Japan’s national sport) are famous for being very big and overweight.

They always eat a simmered, low-fat hot pot dish called “Chanko-nabe” and eat a lot of rice only twice a day. So, a Sumo wrestler diet is very logical way to gain weight.

So why does fat have a deterrent effect? It’s simple.
I’ve stated before that “Base Weight increases by the mechanism of intestinal starvation” and since fat takes around 10 hours to digest, it stays longer hours in the stomach and intestines with a slower digestion rate resulting in undigested food remaining.

Therefore, there will be less chances to trigger the starvation mechanism.

(3)Diet effect (largely categorized within deterrent effect)

As the 2 authors I’ve mentioned above said, “less carbohydrates and more fat will make you slim” is correct. I struggled a lot with eating fatty foods because of having a weak stomach, so I want to explain from that perspective.

It’s not that “carbohydrates are the cause of gaining weight and they are the ultimate bad guys” but rather it’s the difference of characteristics between carbohydrates (*) and fat usage. (*here, I’m referring to polysaccharide such as cereal and starch, but not to sugar)

Fat is difficult to digest so eating fat often leads to undigested food in stomach and intestines. In turn your appetite will settle down and relatively, the absorption rate and absorption amount decreases.

On the other hand, with carbohydrates, they are digested rapidly and make nutrition diluted. So carbohydrates and fat content, it can be said to have the opposite effect, even though a diet has the same calories.

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