...The short answer: yes, theoretically, it is possible to survive without carbohydrates, but there are important nuances.

1. Are carbohydrates "essential" for the body?

Carbohydrates are not considered essential nutrients, unlike:

essential amino acids (protein)

essential fatty acids (fats)

This means the body does not need to obtain carbohydrates from the outside to survive.

Why?

Because the body can:

produce glucose from protein and fat (a process called gluconeogenesis)

use ketones as an alternative energy source

2. What happens if you eliminate carbohydrates completely?

When a person drastically reduces carbohydrate intake:

Glycogen levels (carbohydrate stores in muscles and liver) drop.

Water loss occurs (each gram of glycogen holds ~3 grams of water).

The body switches to fat as its primary energy source.

Ketosis may occur within 1-3 weeks.

This is the basis of the keto diet.

3. A brain without carbohydrates - is it really dangerous?

The brain really loves glucose.
But:

It can get some energy from ketones.

The body synthesizes a minimal amount of glucose itself.

Completely without glucose - no.
Without carbohydrate consumption - yes, it is possible.

4. Is it possible to live that long?

Yes, there are examples:

the keto diet

traditional northern diets with minimal carbohydrates

But it's important to understand:

Long-term risks:

decreased athletic performance (especially strength and explosiveness)

possible decrease in testosterone with too few fats and calories

digestive problems with a lack of fiber

increased stress on the body with an extreme deficiency

5. What about muscle gain and cutting?

To be honest:

For everyday life, you can go without carbohydrates.

For active sports, strength training, and muscle growth, carbohydrates make things much easier.

For hormonal balance, a moderate amount of carbohydrates is often better than zero.

6. Is a complete cutout of carbohydrates a good idea?

Not necessarily.

It's important to understand:

Carbohydrates are not "evil." The problem is usually:

excess calories

processed foods

large amounts of sugar

Conclusion

A person can survive without carbohydrates because the body is able to adapt.

But:

carbohydrates are beneficial for sports and high performance

for hormonal balance, a moderate amount of carbohydrates is often better than zero

nutrition quality is more important than complete abstinence

If the goal is fat loss, then an overall calorie deficit is key, not a complete carbohydrate ban.