Carbohydrates: Friends or Foes?

What Are Carbohydrates?

Carbohydrates are organic compounds, and they can be divided as follows:

• Simple sugar molecules (monosaccharides)
• Sugar compounds (disaccharides)
• Complex structures (polysaccharides)

Our bodies need these compounds for various reasons.

Why Does the Body Need Carbohydrates?

Carbohydrates are indispensable for the body as they support a range of health functions. Here are the key areas where carbohydrates play a central role:

• Energy Source: Carbohydrates are the primary energy source for the body. They are converted into glucose, which is used by the cells as fuel for daily activities and physical performance.
• Brain Function: The brain relies on a constant supply of glucose to think clearly, stay focused, and support cognitive functions. Without enough carbohydrates, mental performance can decline.
• Muscle Function: During sports and physical activity, muscles need glycogen—a form of carbohydrate stored in the muscles. This glycogen provides quick energy and helps maintain endurance and performance.
• Metabolic Regulation: Carbohydrates play a key role in regulating metabolism. They support insulin production, which is necessary to keep blood sugar levels stable and prevent metabolic disorders like diabetes.
• Digestion: Carbohydrates provide fibre, which is important for healthy digestion and helps to avoid digestive problems like constipation.
• Heart Health: Some complex carbohydrates, like those in whole grains and legumes, help lower cholesterol levels and can reduce the risk of cardiovascular diseases.
• Immune System: Carbohydrates are also involved in strengthening the immune system by supporting the production of mucus in the airways, which acts as a protective barrier against pathogens.

Complex Carbohydrates vs. Simple: What’s the Difference?

Simple and complex carbohydrates differ in their chemical structures and how they affect the body. Simple carbohydrates consist of only one or two sugar molecules. These include monosaccharides like glucose and disaccharides like lactose. The body can quickly break them down and use them as energy. In contrast, complex carbohydrates are polysaccharides like starch. The body breaks these down more slowly.

So, there are “better” and “worse” carbohydrates. Which carbohydrate-rich foods are healthy?

Healthy Carbohydrates at a Glance

Healthy carbohydrates are found in foods that are nutrient-rich and minimally processed. These include whole grains, vegetables, fruits, legumes, and potatoes. For example, whole grains are important because they aid digestion and help maintain stable blood sugar levels. Nuts and seeds contain many other nutrients, such as B vitamins, which are involved in a variety of health processes in the body.

How Do Carbohydrates Affect Blood Sugar Levels?

So, carbohydrates aren’t as bad as you might have thought. But what about blood sugar levels? In this context, carbohydrates have recently been getting a bad reputation. Carbohydrates are converted into sugar in the body—specifically glucose—which then enters the bloodstream. But don’t worry: this increase in blood sugar levels is completely normal and necessary, as glucose serves as an energy source.

However, as with many things, the dose makes the difference: too much glucose in the blood can be harmful in the long run. If blood sugar levels remain elevated for an extended period, as can happen with excessive consumption of sugar-rich foods, it can overwhelm the body. The body then tries to remove the excess sugar from the blood by increasing insulin secretion. Over time, this can lead to insulin resistance, where the cells become less responsive to insulin, ultimately increasing the risk of type 2 diabetes and other diseases. Excess glucose can also promote inflammation and oxidative stress, which can accelerate the ageing process.

But, as mentioned, not all carbohydrates have the same effect: complex carbohydrates from whole grains, vegetables, or legumes are digested more slowly, allowing blood sugar to rise gradually and providing longer-lasting energy. It also depends on how you combine your carbohydrates: if you eat carbohydrates on an empty stomach, your blood sugar can spike more quickly. However, if you pair them with proteins, healthy fats, or fibre-rich foods, digestion slows down, and blood sugar levels remain more stable. This not only helps prevent cravings but also ensures sustained energy and supports your concentration and performance throughout the day.

Diets Around Carbohydrates: Low-Carb vs. High-Carb

When it comes to weight loss, there are often two camps: advocates of low-carb and high-carb diets. Both approaches can be effective, but they work in different ways. A low-carb diet drastically reduces carbohydrate intake, forcing the body to rely more on fat as an energy source. This can lead to rapid weight loss, particularly through the loss of water weight in the first few days. However, a long-term reduction in carbohydrates can impair energy and performance, especially during intense physical activities.

On the other hand, high-carb diets focus on a high intake of healthy, complex carbohydrates that provide a constant energy supply. This diet can be especially beneficial for people who exercise a lot or want to build muscle mass. It provides enough energy for intense training and helps keep metabolism active. Ultimately, it depends on your individual goals and needs: while low-carb diets can deliver quick results, a balanced high-carb diet offers long-term support for your fitness and health.

Termic Effect of Food (TEF): What Is It?

The thermic effect of food (TEF) refers to the additional energy expenditure that occurs during the digestion, absorption, and metabolism of food. Proteins have the highest TEF, meaning they require more energy to process, while carbohydrates have a lower TEF and therefore stimulate the metabolism less than fats. For carbohydrates, the TEF usually ranges between 5% and 10%.