What do Carbohydrates do?

Carbohydrates play a crucial role in fueling our bodies with energy. Diverse in their forms, they can be classified into three main categories: simple, complex, and refined carbohydrates.

When incorporated thoughtfully, carbohydrates can be integral to a nutritious diet. But be warned, overconsumption or opting for the wrong types of carbs can lead to weight gain and other health complications.

In this piece, we delve into the essential role of carbohydrates, their origins, how the body metabolizes them, and how to make informed choices about which ones to include in your diet.

Function of carbohydrates

Carbohydrates serve as a principal source of energy for our bodies. Although proteins and fats can also be metabolized for power, carbohydrates are the preferred fuel source.

The body may tap into proteins and fats for energy without sufficient carbohydrates. However, given protein’s essential role in numerous bodily functions, such as tissue repair and growth, the body is typically reluctant to use it as an energy resource.

Carbohydrates are metabolized into glucose in the body. With the assistance of the hormone insulin, this glucose moves from the bloodstream into the body’s cells. It’s crucial to note that glucose is the primary energy currency for all cellular functions.

Where do carbohydrates come from?

Carbohydrates are primarily obtained from our diet, particularly from plant-based foods, which are a rich source of these essential macronutrients.

Carbohydrates comprise sugar molecules known as saccharides, compounds composed of carbon, hydrogen, and oxygen atoms. These carbohydrates form a substantial part of an individual’s daily nutrient consumption.

Types of carbohydrates

Carbohydrates are generally categorized into simple or complex based on the number of sugar molecules they possess.

Simple Carbohydrates

These consist of one or two sugar molecules in glucose, fructose, sucrose, and lactose. You can naturally source simple carbohydrates from:

  • Fruits
  • Fruit Juices
  • Milk and Milk Products

Complex Carbohydrates

Complex carbohydrates have more intricate chains of sugars, such as oligosaccharides and polysaccharides. They are also sources of fibre and starch. Examples of foods with complex carbohydrates include:

  • Whole Grains (certain bread types, cereal, pasta, and rice)
  • Peas and Beans
  • Fruits and Vegetables

Refined Carbohydrates

Refined carbohydrates have undergone processing, removing certain components like fibre and minerals. Such carbohydrates often include sweeteners and high fructose corn syrup, commonly added to processed foods. Examples of refined carbohydrates are:

  • White Bread, Pasta, and Rice
  • Processed Breakfast Cereals
  • Cakes, Sweets, and Baked Goods
  • Sweeteners and High Fructose Corn Syrup

How does our body process carbohydrates?

Carbohydrates get broken down into glucose in the body, serving various functions such as:

  • Providing a steady energy supply for bodily functions
  • Offering an immediate energy boost during physical activity
  • Acting as an energy reserve stored in muscles or the liver for later use

When the body has enough stored energy and doesn’t require more, it converts the excess glucose into fat, potentially leading to weight gain.

Glucose must be promptly moved out of the bloodstream as its prolonged presence can be harmful and toxic. Post a meal, the pancreas secretes insulin to facilitate the movement of glucose into the body’s cells for utilization or storage.

Insulin plays a crucial role in preventing excessively high blood sugar levels. However, a diet loaded with sugary foods and carbohydrates can over-rely on the insulin response, possibly leading to health complications such as diabetes or obesity.

Unhealthful vs healthful carbohydrates

Consuming more carbohydrates than the body needs can lead to excess glucose being stored as fat. Individuals who lead an active lifestyle or frequently exercise may quickly utilise this stored energy. However, unused carbohydrates can contribute to weight gain for sedentary people.

Opting for complex carbohydrates, such as whole-grain bread, brown rice, and vegetables, can be a healthier choice. These food items release energy slowly, keeping one satiated for longer.

Starchy vegetables are healthier options, including sweet potatoes, parsnips, squash, pumpkin, beets, yams, turnips, and swedes. Legumes, such as beans and peas, packed with complex carbohydrates, can also form a significant part of a nutritious diet.

Grains constitute a major part of many people’s diets. The Dietary Guidelines for Americans 2015-2020 suggest consuming six ounce-equivalents of grains daily as part of a 2,000-calorie diet. Half of this should be whole grains instead of refined or processed ones. One way to ensure this is by choosing 100% whole grain products or foods containing at least 50% whole grains.

While simple and refined carbohydrates like white bread, pasta, white potatoes, and sugary snacks and drinks can provide an immediate energy boost, they are quickly absorbed by the body and may not keep one full for long. This could lead to overeating, highlighting the importance of mindful consumption.

Adopting healthier alternatives can significantly contribute to maintaining a balanced diet:

  • Opt for whole-grain varieties instead of regular white pasta or rice.
  • Consider having a quinoa salad or a baked sweet potato instead of a sandwich with white bread, and add an assortment of vegetables to your meal.
  • Instead of consuming processed breakfast cereals, prepare overnight oats by soaking whole grain oats in coconut milk and cinnamon, then add blueberries for an extra nutrient boost.
  • Substitute a pizza slice with a wholesome and satisfying soup filled with vegetables, lentils or beans.


Carbohydrates are crucial for fueling the body and enabling it to perform at its best. Individuals’ carbohydrate needs may vary depending on their lifestyle, weight, and physical activity levels.

Maintaining a balanced diet for most people involves incorporating complex carbohydrates while minimizing the consumption of refined carbohydrates.

Making mindful choices about the types of carbohydrates one consumes can promote a healthy blood glucose level and reduce the risk of related health issues.