You may be eating too much rice, noodles, bread, and sugary foods.
Eating too much of these foods can cause your blood sugar levels to rise quickly.
When blood sugar levels rise, the body suffers various damages, so the pancreas tries to lower blood sugar levels by secreting 'insulin'.
When the blood sugar level rises and falls gradually, there is no problem, but when the blood sugar level rises rapidly, the body secretes a large amount of insulin to quickly lower the blood sugar level, and the blood sugar level drops more than necessary.
These rapid changes in blood sugar levels can cause symptoms such as drowsiness, sleepiness, or psychological anxiety.
People who usually eat a lot of this type of food should be especially careful.
If the state of severe blood sugar level fluctuations continues, it is easy for chronic hyperglycemia to occur, which can lead to diabetes.
--- p.41

It stores energy, processes toxins such as alcohol and ammonia found in food, produces bile that aids in the digestion and absorption of fat, etc.
He is taking on various roles on his own.
Because the interval between meals is short and food keeps coming in, the liver has to work 24 hours a day without rest, so it gradually becomes exhausted.
When the liver's function declines due to fatigue, toxins and waste products that should be detoxified by the liver remain in the body, and the amount of energy produced decreases, causing the body to feel chronically fatigued.
Additionally, you may lose your taste for alcohol, have a decreased appetite, and develop diseases and disorders of the liver itself, such as hepatitis, fatty liver, cirrhosis, and even liver cancer.
--- p.52

There's a reason I'm so fixated on 16 hours.
First, after about 10 hours have passed since the last time you ate, the sugar stored in the liver is consumed, allowing fat to be broken down and used as energy.
And after 16 hours, this time 'autophagy' starts functioning in the body.
Here, I will briefly explain the unfamiliar but very important word ‘autophagy’.
Our body is made up of about 60 trillion cells, and cells are made primarily of proteins.
In daily life, most of the old or broken proteins are excreted from the body, but the ones that are not excreted accumulate inside the cells, weakening the cells and causing various physical abnormalities and diseases.
Meanwhile, we get nutrients from our regular food and make the proteins we need.
However, if nutrients are not available for some reason, the body tries to make protein from what is already in the body to survive.
--- p.74

For example, autophagy is not activated until about 16 hours after the last meal.
In other words, if you don't create a fasting period, you can't activate autophagy and create new cells.
Conversely, even if it's just once a week, setting aside a few hours of "food-free time" alongside your sleep time can help your intestines rest, reduce fat, improve blood quality, and even reap the benefits of cellular regeneration through autophagy.
Meanwhile, in 2016, Professor Yoshinori Ohsumi of Tokyo Institute of Technology won the Nobel Prize in Physiology or Medicine for his research on autophagy.
It can be said that autophagy is currently attracting worldwide attention.
'Eating on an empty stomach' resets the damage caused to the body by eating three times a day and overeating, and revives the body from within.
An empty stomach is the best medicine.
--- p.78

Things start to happen where you can't absorb enough nutrients and can't 'cleanly excrete waste products'.
Additionally, when the intestinal environment deteriorates, immunity also declines, making the body's condition worse and making it vulnerable to disease.
However, if you create a regular fasting time even once a week, your intestines can get enough rest.
As a result, the fatigue in the intestines will be reset and they will be able to properly perform their duties, which will improve symptoms such as diarrhea, constipation, allergies, or poor condition.
Furthermore, it is said that when there is a temporary nutritional deficiency due to fasting, the amount of antioxidant enzymes that remove active oxygen increases, reducing the amount of active oxygen.
--- p.90

Some of you may be thinking, "If I wake up and don't eat anything for 4-5 hours, won't I get hungry and have a hard time?" or "I won't be able to concentrate on work."
Especially for the first few days, due to long-term habits, you may feel the urge to eat something even when you feel even a little hungry.
So what should you do in such a situation? Simply enduring it isn't easy, so I recommend eating nuts (preferably roasted, without any added seasoning).
--- p.103

A diet that revives the body by creating an 'empty stomach' without overdoing it. I actually train along with this diet every day. For example, I do push-ups and abdominal exercises in the morning and stop when I feel tired.
Excessive exercise can also cause the generation of active oxygen.
Anyway, keep in mind that you should do it within the limits of what you can do without overdoing it.
It is also said that a person weighing 60 kg burns about 100 kcal when slowly climbing up and down stairs.
This is equivalent to the calories burned by a 60kg person jogging for about 12 minutes.
--- p.125

Dopamine is called the 'brain's reward system', and beta-endorphin is called the 'brain's drug'.
It is secreted when a desire is fulfilled (or when it is known that it will be fulfilled) and gives a person a feeling of pleasure. Because the pleasure is so great, it is said to have strong dependence and addiction.
And carbohydrates are known to increase dopamine and beta-endorphin.
This is why we feel happy when we eat sweet foods, and once we consume carbohydrates, we continue to crave them.
So, as carbohydrate-laden foods sell well and more and more carbohydrate-laden foods are available in the world, we end up choosing to eat them.
--- p.137

The term fatty liver disease may make you think it is common in obese people, but there are also many people who are thin but have fatty liver disease.
In the past, it was thought that the main cause of fatty liver was excessive alcohol consumption.
However, recently, the number of people with fatty liver disease due to causes other than alcohol, such as excessive intake of carbohydrates and fats, has been increasing.
When fatty liver disease occurs, excessive fat accumulates in liver cells, increasing the permeability of the cell membrane or destroying the liver cells. This causes enzymes in the liver cells to flow into the blood, increasing the levels of GOT and GPT (both enzymes originally found in liver cells) in the blood.
--- p.142

Since ancient times, 'excessive salt (sodium) intake' has been considered the biggest cause of high blood pressure, but recently, high blood pressure triggered by visceral fat obesity has become common.
When visceral fat increases and insulin function declines, the pancreas secretes large amounts of insulin, which activates the sympathetic nerves and raises blood pressure.
In addition, insulin has the function of interfering with the excretion of salt from the pancreas, which increases the salt concentration in the blood and causes high blood pressure.
Furthermore, hypertrophied large fat cells secrete angiotensinogen, a substance that increases blood pressure.

--- p.178