Mental instability resides in the waves of blood sugar. — "90% of Mood is Blood Sugar"

For some reason, my mood fluctuates throughout the day.
Even if I feel light in the morning, a sense of impatience washes over me by the afternoon.
I can't shake off my fatigue on weekends, and I get irritated for no reason.

This book, "90% of Mood is Blood Sugar," quietly exposes the true nature of those "invisible waves."
The keyword is "blood sugar level."
It claims that everything from emotional swings to lapses in concentration can be explained by this single "biological graph."

Blood sugar levels and mental state move to the same rhythm

The author points out the perspective that "blood sugar level equals energy stability."
If blood sugar levels spike, the brain becomes high-tension for a moment.
However, the subsequent sharp drop disrupts the autonomic nervous system, causing irritation and fatigue.

In other words,mood waves resemble the "waveform of blood sugar levels".
To maintain a calm mood, you need to regulate the "curves" within your body.

There was a strange persuasiveness in this sentence.
Mental strength is not about mental training, but aboutleveling out internal energy.

Another key to regulating the autonomic nervous system

Blood sugar levels and the autonomic nervous system are closely linked.
When in a state of low blood sugar, the body judges it as a "life-threatening crisis" and secretes adrenaline.
As a result, impatience, anxiety, and anger well up.

Conversely, when blood sugar is stable, the parasympathetic nervous system becomes dominant,
the mind clears, breathing deepens, and emotions are quietly settled.

The core of this book lies here.
In a sense, this is a book that "physiologically reconstructs" the "logic of the heart."

"Regulating" rather than "trying hard"

Many modern people mistake a lifestyle that disrupts blood sugar for "effort."
Coffee only in the morning, bread and sweets for lunch, and alcohol at night because you're tired.
While it may look energetic at first glance, in reality, it is a state of "borrowing energy" through the ups and downs of blood sugar.

As a result—
・Feeling sleepy after meals
・Losing concentration in the evening
・Waking up around 2 AM
・Having no desire to do anything on days off

These are not "mental disorders," but "rebellions of blood sugar."

Regaining quiet energy, "genuine vitality"

What this book proposes is a lifestyle rhythm that creates "unwavering vitality."
It is not about treating sugar as an enemy, but a way of life that"uses blood sugar levels smoothly."

For example,

• incorporating protein and fats into breakfast

• Design snacks as a "buffer" rather than "emergency energy"

• Get sugar circulating with a light walk after meals

• Avoid caffeine late at night

It is not about "stoic dietary restrictions," but rather closer to a
physical strategy for designing emotional stability.

Blood sugar control is a technique for increasing the "clarity of thought."

What I felt as I read on was that
what blood sugar stability brings is not merely health.

Thoughts become clear, and judgments become calm.
Unnecessary anxiety decreases, and you can focus on the "now."

In other words, regulating blood sugar is also an act of
reducing brain noise and beautifying the UI of the mind. It is a kind of "thought with white space" that resonates with Apple's design philosophy.

Do not change your mood; "design" your mood.

You cannot change your mood through willpower alone.
However, if you design the state of your body, your mood will naturally settle.

"90% of Your Mood is Blood Sugar" teaches us the extremely practical and gentle truth that
"mental stability is born not from the power of thought, but from physiological stability."

Don't rush, don't get angry, don't waver.
To borrow the words from this book,
that is "true vitality."

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