Learn about the different roles that carbs play to maximize your nutrition knowledge and apply to your diet and fitness.
January 23, 2025
Carbohydrates are one of the three macronutrients that our body uses (protein, fat, and carbs). It plays a crucial role in our body as its preferred energy source. Carbs are typically found in fruits, vegetables, dairy, and grains. Over the years, different foods have gotten a bad rap. At one point, it was fat, and at other times, it was carbs. However, as we’ll learn in this article, both simple and complex carbs have a role in our body, and we can strategically leverage these roles to our advantage.
Understanding Carbs
Let’s get real- carbs aren’t the villain. Carbohydrates are repeating chains of carbon, hydrogen, and oxygen (CH2O). Due to their longer length, longer chains of dozens of CH2O’s are classified as complex carbs. Simple carbs, on the other hand, are composed of shorter CH2O chains. The length of the chain has one significant impact that everyone should know about. The longer the chain of CH2Os, the longer they take to break down and digest.
The three major categories of carbs that come from the food we eat are:
Simple Sugars: Monosaccharides and disaccharides, or single chains, such as sucrose, glucose, fructose, lactose, and galactose. (chem.librytexts)
Starches: Polysaccharides have very long chains (up to hundreds) of repeated glucose molecules.
Fiber: A source of carbohydrate that our body can’t break down into glucose and instead passes through our body. There is soluble fiber that can be dissolved in water and insoluble fiber that cannot be dissolved in water (nutrition source).
When carbs are broken down, they are broken up into their pieces, called glucose, or converted to glucose if they were a different type of carb, such as sucrose, lactose, etc. The effect of a more extended breakdown and digestion phase means that the glucose released into the blood will spread out more over time rather than a lot at once. In sum, the longer the chain:
-
The fuller you’ll feel
-
The smaller the blood glucose spike will be
Does this mean that complex carbs are always better? Not necessarily. As we’ll discuss, sometimes our body will need carbs that can be rapidly broken down and made available as energy. However, for most people, most carbs consumed should be complex.
Simple Carbs
So far, simple carbs sound less healthy and they can often be. However, simple carbs can also be found in some healthy foods, such as fruit or dairy, with other healthy things like vitamins, fiber, or minerals. Some simple carb sources started as complex, such as refined grain products like white rice, pasta, and bread.
These refined products had their germ and bran removed, leaving only the endosperm. Endosperm contains most energy, but germs and bran contain many critical nutrients such as fiber and vitamins. However, most foods with lots of simple carbs are foods we want to have less of, including:
-
Sweetened drinks such as coffee, tea, juice, and soda
-
Desserts such as pastries, cookies, etc
-
Chips, crackers, snack bars,
As discussed in the “Understand Carbs” section, simple carbs are digested quickly, providing energy quickly. This is why most simple carb foods have a high glycemic index, rapidly providing glucose to the bloodstream. However, if you pair simple carbs with something with fiber, protein, or fat, this blood glucose spike can be slower. Some simple carb foods like apples already have fiber in them!
If you need energy quickly, such as during an endurance event or feeling faint from not eating for a while, simple carbs can provide energy that your body can use immediately. This is why endurance athletes eat energy gels or type one diabetics consume juice—to get rapidly digestible energy.
Most of the carbs from your diet should not come from simple carbs. Processed foods high in simple carbs usually have a lot of other questionable ingredients in them. They also contribute to overeating, high blood lipid levels, higher blood pressure, and diseases such as diabetes, which also often come with a set of other deadly comorbidities.
Complex Carbs
Complex carbs are usually more nutritious than simple carbs because they have more nutrients. As discussed earlier, complex carbs have not been altered to remove any part of the food, leaving all of that fiber, vitamins, minerals, and even sometimes protein and fats. If you look at the differences in nutrition labels between whole flour and white flour or brown rice and white rice, you’ll see many of these healthy nutrients in the whole grain option.
Due to those longer CH2O chains, complex carbs also take longer to digest, increasing feelings of satiety. Complex carbs have a lower glycemic index, which means the release of glucose into the blood is more controlled, allowing for more sustained energy delivery from the blood to the body's cells. Here are some examples of complex carbs:
-
Whole grain breads, pastas, and rices
-
Tubers such as potatoes and yams
-
Legumes such as lentils, chickpeas, and beans
-
Other grains like quinoa, bulgar, and farro
Rather than demonizing carbs, begin to understand which type of carb your body needs throughout the day. Aim to ingest your highest carb intake before workouts or earlier in the day, rather than right before bed. Happy fueling!
References
