What Carbohydrates Do and How to Get Them: Nutrients and How to Get Them (2)

Written by: 稲山 未来 (Registered Dietitian)

Last time, I explained protein, the nutrient that builds the body. This time, let’s learn about carbohydrates, which, like protein, are one of the three major nutrients.

Carbohydrates are the energy that moves the body

Carbohydrates provide the energy we use to move our bodies and run our brains. They turn into energy quickly, which is why eating or drinking something sweet when you’re tired perks you up so fast.

Their other important role is to fuel the brain. The brain normally relies on carbohydrates (glucose) for almost all of its energy. So when carbohydrates run short, concentration drops and we feel foggy. We’re told to eat a good breakfast because the brain needs energy to concentrate on things like studying.

How do we get carbohydrates?

The carbohydrates discussed here are the digestible kind (sugars and starches), found in grains, potatoes, fruit, sugar and so on. A simple way to think of them is as the sweet component of sugar.

Because carbohydrates are the body’s main source of energy, it is considered ideal to get 50 to 65 percent of your daily energy intake from them.

Specifically, that means about one regular bowl of rice at each meal (three bowls a day), plus carbohydrates from fruit equivalent to about two mandarin oranges a day, and the sugar used in cooking.

Of course, you can swap one of the three bowls of rice for noodles or bread. Make sure each of your three meals includes a staple food: rice, noodles or bread.

What happens when carbohydrates run short?

So if carbohydrates, the body’s energy source, run short, does the body stop working?

No, it doesn’t. When carbohydrates run short, fat and protein, the other two major nutrients, step in as energy sources instead.

However, the brain cannot use fat directly as an energy source, so when carbohydrates run short, the mind becomes sluggish. We can think clearly because we are getting enough carbohydrates.

Is eating too many carbohydrates bad?

Excess carbohydrates are broken down in the body and stored in the liver and muscles as glycogen, which is used to power movement. Any carbohydrates still left over are stored as body fat, a source of energy for times of need. Carrying a lot of this body fat is what we call obesity.

In middle age, obesity is linked to conditions such as metabolic syndrome and is very harmful to health, so people are told to lose weight. In older people, however, fat cannot simply be called the villain.

That is because older people often start eating much less quite suddenly after some trigger, such as a fall or the emotional stress of losing someone close. They also feel hunger less than when they were young, so they tend to neglect meals.

And it is precisely when appetite shrinks that body fat, this “reserve for times of need,” proves useful. When meals don’t provide enough energy, the body breaks down body fat to produce energy, so it can serve as reserve nutrition until appetite returns.

Without this reserve, the body has to squeeze energy and nutrients out of itself somehow, and the person loses weight and their immunity declines further.

Do slightly plump older people live longer than thin ones?

When immunity declines, people become more prone to infections, and you can imagine that infections lower their quality of life even further.

Recently, undernutrition itself has come to be seen as a major risk to quality of life, and it is even said that older people who are slightly on the heavy side stay healthier and live longer than those who are thin. If you need to manage your diet because of diabetes or another condition, follow the instructions of your doctor or registered dietitian.

Finally

The key point is that carbohydrates are the energy source for both body and brain. The brain in particular normally runs mainly on carbohydrates, so to avoid running short, make sure to eat a staple food such as rice, noodles or bread at each meal.

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About the author: 稲山 未来 (Registered Dietitian)

This article is a contribution from a medical or care professional, re-edited by our editorial team. It provides general information as of the time of writing, and symptoms and circumstances differ from person to person. For specific decisions, please consult your doctor, dentist, pharmacist or another professional.

This is an English translation of a column originally published in Japanese by Next Co., Ltd.

About Next Co., Ltd. We are a Tokyo-based company working in Japan’s senior care and end-of-life planning field. Alongside these expert columns, we publish professional training textbooks and support businesses entering Japan’s eldercare market. More expert columns | Our English textbook | Contact us