Overactive nervous system: how to recognize it and why it affects metabolism, digestion and sleep

Frank Suárez taught that to understand metabolism, it's not enough to only look at food, weight, or visible symptoms. To achieve better results, a person needs to observe what is controlling the body from within. And one of the most important influences, he explained, is the autonomic central nervous system.

This system works automatically. A person doesn't have to think about how fast their heart beats, if they are digesting, or if the body is eliminating or detoxifying. All of this happens without one having to consciously order it.

Therefore, in Frank's teaching, understanding the nervous system was not a minor detail. It was a key piece to understand why some people react to certain foods in one way, while others react completely differently. From this arises one of his most important observations: there is no single diet that is good for everyone, because not all bodies are the same.

The nervous system and metabolism control

Frank Suárez explained that the autonomic central nervous system controls vital body functions: glands, hormones, circulation, digestion, elimination, and detoxification. In other words, many of the functions that determine the body's energy are influenced by this automatic system.

Within this teaching, Frank spoke of two main tendencies: the excited nervous system and the passive nervous system.

The importance lies in discovering which of the two predominates in a person's body. A person with an excited nervous system needs to adjust their diet and lifestyle in one way. A person with a passive nervous system needs to make different adjustments.

This is where many people get confused. They see that a way of eating works for someone and think it should work for them too. But Frank insisted that we are not all the same. One person's metabolism may need one type of support, while another's may need something different.

Why identifying the dominant nervous system changes the strategy

For Frank, success did not depend on following a generic diet, but on understanding the body. If a person has an excited nervous system and eats in a way that is not beneficial for them, they can end up with digestive problems, light sleep, difficulty resting, and a metabolism that does not improve as it should.

The key is to observe signals. The body speaks, but you have to learn to understand its language.

Frank explained that people with an excited nervous system have certain dominant characteristics. It doesn't mean that all people have all characteristics at the same level. Some may have a slightly excited nervous system, others moderately excited, and others very excited. What changes is the degree.

However, if a person recognizes any of the main signals, it indicates that their body has an excited tendency and should be treated as such.

First sign: difficulty digesting red meat

One of the characteristics Frank pointed out in people with an excited nervous system is that they often don't digest red meat well or take a long time to digest it.

The person may eat red meat and feel that it "stays there," like a heavy discomfort. The body seems not to handle it easily. In some cases, they don't even like red meat, because the body naturally rejects it.

This observation was important because for Frank, digestion gave clues about the state of metabolism. If a food feels heavy, takes time to go down, or causes discomfort, the body is providing information.

In the case of the excited nervous system, this difficulty with red meat was one of the clearest digestive signs.

Second sign: saturated fats upset the stomach

Another characteristic of the excited nervous system, according to Frank, is that saturated fats can upset the stomach.

Here he mentioned foods such as pork, pork chops, fatty foods, fatty cheeses, and also red meat when it has a lot of fat. The explanation he gave was simple: the excited nervous system is an acidic system. And since the body is already acidic, it rejects more acid.

Frank reminded us that fats are fatty acids. Therefore, in a body that is already very acidic, fat can become an additional burden. The person eats fatty foods and feels that they don't sit well with them.

This was another practical way to observe the body. It was not about saying that everyone should eat the same. It was about looking at how each organism reacts. If saturated fats upset the stomach, Frank interpreted it as a sign that the person has an excited nervous system.

Third sign: poor digestion when eating late at night

The third digestive characteristic Frank taught was poor digestion when a person eats late at night.

A person with an excited nervous system may eat during the day and tolerate it better. But when they eat late, especially after a certain hour in the evening or at night, the food can feel heavy. There may be gas, discomfort, or the sensation that the body did not digest well.

Even the next day, the person may wake up with the discomfort that digestion was not completed properly.

Frank explained that the body with an excited nervous system does not digest well at night. By giving it food late, a problem is added. The food is not digested as it should, it begins to decompose, and this produces more acid within the body. This increase in acidity can further excite the body.

Here we see one of the central ideas of his teaching: the body does not fail for no reason. There is cause and effect. If a person observes what happens when they eat late, they can learn something very valuable about their metabolism.

Fourth sign: eating late makes it hard to sleep

Digestion and sleep are connected in this teaching. Frank explained that a person with an excited nervous system may have difficulty sleeping if they eat late at night.

The person eats, goes to bed, and starts tossing and turning. They can't fall asleep easily. They may stay watching TV, feel uncomfortable, or simply not be able to sleep.

This happens because the excited body does not handle nighttime digestion well. Instead of resting, the body receives a burden. And when the body receives that burden at a time when it should be calm, it becomes more excited.

For Frank, this was very important because sleep is related to metabolism. If a person doesn't sleep well, the body doesn't recover well. And if the body doesn't recover, its energy doesn't work well either.

Therefore, a simple habit like eating late can become a barrier to improving metabolism, especially in a person with an excited nervous system.

Fifth sign: light sleep and easy awakening

The last sign Frank mentioned relates directly to sleep quality. People with an excited nervous system usually have light sleep and wake up easily.

It's not just that they have trouble sleeping. It's that, even when they do sleep, they don't necessarily enter a deep sleep. Frank talked about different levels of sleep and emphasized that the deepest level is the most restorative.

A person with a passive nervous system can sleep so deeply that almost nothing wakes them up. In contrast, a person with an excited nervous system can wake up at the slightest thing. Their sleep is more fragile.

This helps to understand why two people can go to bed at the same time and wake up with very different energy levels. It's not just about how many hours they spent in bed. The depth and quality of rest also matter.

The diet must be adjusted to the body type

After identifying these signs, Frank Suárez taught that people with an excited nervous system should adjust their eating habits. In general terms, he spoke of a much more vegetarian diet, with vegetables, salads, white meat, chicken, turkey, and fish.

He also noted that for this body type, there should be almost no fat, because fat could be very problematic for people with an excited nervous system.

He also highlighted the importance of water. In this teaching, an excited person needs a lot of water, because their body tends to be very acidic and can experience digestive problems, constipation, dental problems, and difficulty sleeping.

He also mentioned aids like potassium and magnesium, especially because these people often have problems related to constipation, acidity, digestion, and sleep.

The idea was not to complicate a person's life, but to help them observe their body and give it what it needs. Because when you stop fighting with your body and start understanding it, things begin to make more sense.

Not all bodies need the same thing

One of Frank Suárez's strongest teachings was that metabolism cannot be approached with a "one-size-fits-all" mentality. A diet can help one person and harm another, not because the diet is inherently good or bad, but because bodies are not all the same.

A person with an excited nervous system needs to support their body in a way that helps it calm down, digest better, rest better, and manage energy more effectively. If that person insists on eating foods their body rejects, especially late at night, they may remain trapped in the same cycle of poor digestion, bad sleep, and slow metabolic progress.

On the other hand, when a person identifies their signals, they can start making smarter adjustments. It's not about guessing. It's about observing.

Conclusion: the body gives signals, but you have to learn to listen to them

Frank Suárez taught that knowledge is a powerful tool to recover metabolism. Many people try to resolve symptoms without understanding the cause. But the body is always communicating something.

If a person doesn't digest red meat well, if saturated fats upset their stomach, if eating late causes poor digestion, if eating at night prevents them from sleeping, or if they have light sleep and wake up easily, these signs may indicate an excited nervous system.

And if the body is excited, it needs to be treated as such.

The teaching is simple but powerful: metabolism is not improved by fighting against the body, but by understanding how it works. When a person learns to identify their dominant nervous system type, they can adjust their diet and lifestyle with greater precision.

Because in the end, as Frank taught, the truth always prevails.