Simple Carbohydrates vs Complex Carbohydrates

Carbohydrates are one of the three macronutrients, alongside protein and fats the body needs to function properly. They’re the body’s preferred source of energy.— while we burn fat and protein for energy, the body prefers carbohydrates for fueling basic metabolic functions. Carbohydrates can be broken down into different groups based on their structure – and how they are utilized in the body. Carbohydrates are usually categorized as either simple or complex. This article explains the difference between the two types, their benefits, and which foods are sources of each type.

• What are carbohydrates?
• What are simple carbohydrates?
• What can simple carbohydrates be useful for?
• Simple carbohydrates to avoid
• What are complex carbohydrates?
• Benefits of complex carbohydrates
• Complex carbohydrate foods

What are carbohydrates?

Carbohydrates are one of the primary sources of glucose, which the body uses for energy. Foods high in carbohydrates typically contain high levels of starch, fiber, and sugars — these nutrients have different chemical structures and are processed by the body in different ways.¹

Complex carbohydrates are nutritionally dense and typically contain higher levels of fiber and starch. Because of this they often take longer to digest. Foods higher in sugar digest more quickly, and are classified as simple carbs.

What are simple carbohydrates?

Simple carbs are also known as sugars, and include glucose, dextrose, and lactose. They digest quickly and can be used for energy or stored in the liver or muscles for future use. Because they can be easily converted into glucose, they’re considered “high GI (glycaemic index)” carbs. While you may think of sugars as added for flavor and sweetness, sugars also occur naturally in foods,: such as fructose in fruit or lactose in milk.

What can simple carbohydrates be useful for?

Simple carbs have a bad reputation, but they can be useful. If you’re getting ready for a workout (or in the middle of one) and need a quick burst of energy, a dose of a quick-digesting carb like dextrose can be ideal. If you your blood sugar is low (feeling weak or tired or shaky), some simple sugars can be helpful.

Exercise that lasts longer than an hour, such as marathon training, requires sources of simple carbs (like energy gels or dextrose) to keep muscles replenished.²

Simple carbohydrates to avoid

While our body needs all types of carbohydrates, some high-sugar foods that have limited health benefits should generally be avoided in high quantities. Check nutrition labels for the amount of “added sugar” in a food rather than overall carbohydrates. Avoiding foods with five or more grams of added sugar is a good general guideline to follow. Examples of foods high in these simple carbs include:

• Packaged baked goods, cookies, biscuits

• Sweetened fruit- flavoured beverages

• Sweetened breakfast cereals

• Cakes

• Sodas

What are complex carbohydrates?

Complex carbohydrates are larger chains of simple sugars, fibre, and starches. These larger molecules digest more slowly into glucose and raise blood sugar more slowly, making them ‘low GI’ carbs. They provide energy over time and can be more filling than simple carbs. Complex carbohydrates often occur in nutrient- dense, plant- based foods like fruits, vegetables, and grains. These foods also contain high levels of vitamins and minerals that are good for our health.

Benefits of complex carbohydrates

Complex carbohydrates are ideal for when you need sustained energy levels. Consuming complex carbs more than one hour before your workout can help you stay energised and ready for a challenge. Long-distance cardio, such as running or swimming for more than 30 minutes, uses complex and stored carbs for sustained energy. This is why marathon runners “carb load” before a long-distance race.

Complex carbohydrates are also key for recovery after a workout. They help get protein to the muscles for recovery, and are crucial for replenishing stored carbs burned during exercise.2 A carbohydrate source (alone or as part of a meal) within two hours of exercise can help restore your muscles’ glucose levels.³