Carbs, Fiber, and the Glycemic Index (Oh My!)

Carbs, fiber, and the glycemic index. All of these terms have been thrown at you your entire life, diets are low-carb, foods are high-carb, some are high fiber, low fiber, etc. This can be pretty overwhelming, I know! Well, let me try and break it down for you.


Carb’s fulfill several roles in human physiology. The body’s priority is to make sure that the brain has sufficient glucose to function and to provide energy for muscles to function correctly, and efficiently. Without the proper intake of carbs, the ability to make glucose can still occur, but is then derived differently than when it is absorbed and assimilated from ingesting carbs. Glycogen is the usable form of glucose for muscular work. In fact, carb stores are retained in both muscle and liver tissues as glycogen. By design, glycogen has the ability to provide energy over an extended period of time, which is why you see marathon runners loading up on carbs and pasta the night before a big race.

Your body needs carbs. However, what you do need to master is understanding the difference between carbohydrate types and the timing of their intake. I don’t recommend a client to cut carbs or go on a low-carb diet because it’s a source of energy, fiber and vitamin c. If this is cut from the diet, and entire macronutrient is being cut out. This doesn’t mean go crazy and load up on carbs, you still need to monitor your intake. Many experts in nutrition all agree that you need to keep your intake of carbs to about 45% to 65% of your daily food intake and calories from carbs.

I’ve noticed in the fitness industry that many trainers will discourage simple carbs, as they tend to alter energy levels acutely and cannot provide enough fuel for people who are active. Again, there is a proper time and circumstance for taking in simple carbohydrates. Still, carbs need to be better understood in order to make better decisions. As a nutritionist, I don’t expect you to revisit chemistry class and remember all of this, but I do want to at least plant a little seed in the back of your mind about the many types of carbs out there. It’s more important to count fiber than carbohydrates, and we will touch on fiber more in the next section.

Simple carbohydrates are known as monosaccharides and include any food ingredients that end in “ose”, like fructose, galactose, and glucose, etc. These are carbs that you don’t want to overdo, but you don’t want to completely remove either. Consuming naturally-occurring sugars is still needed for the body to function at its best. Cutting out refined sugars is part of the detox process, and unlocking your weight loss resistance. Carb’s influence everything from anabolic reactions to energy supplies, so having a good balance only comes with a better understanding of carbs.

Now we delve even deeper, diving into complex carbs, which are derived from plants that contain both starch and dietary fiber. These include vegetables, potatoes (don’t overdo white potatoes), dried beans, fruits, etc. Animal products contain little, if any carbs. These complex carbs you want to incorporate as the largest part of your daily intake, but again in right amounts and at the right time.  Energy from complex carbs are more of a slow and steady burn, which can prevent peaks and valleys in your energy profile. The secretion of insulin is also more controlled in the presence of complex carbs. Complex carbs do have a similarity with their counterpart (Simple Carbs), in that they are both broken down into glucose and then eventually are used to provide energy for human function and performance. However, where the two differ most is the complex bonds of multiple molecules linked together, meaning it’s a much slower process within the body to make glucose, and to then digest them properly. Many times this will make you feel fuller for a longer period of time, meaning you won’t be as hungry as often. This will allow your gut time to heal since you’re not bombarding your system with foods wreaking havoc, and give your body time to regulate its hormones, often times helping overcome insulin resistance, among other hormonal issues.

Net carbs are those carbs that have a direct impact on blood sugar. You calculate net carbs by subtracting the fiber from the total carbohydrate count of a food (using the food label). The FDA hasn’t officially endorsed the use of net carbs on food labels, but with the sudden advance in knowledge of nutrition, I feel like it’s only a matter of time.

Leaky Gut


“Bean’s, bean’s, the magical fruit… the more you eat… the more you…” well you know the rest. So you’re all too familiar with the term fiber, you’ve seen ads on TV showing how to supplement your diet with it, and you see a lot of foods labeled now “high in fiber” or “great source of fiber”. But do you actually know what fiber is or does to your body?

It’s extremely rare to meet someone who consumes enough fiber. Even clients who take fiber supplements, possibly aren’t consuming enough fiber. Mostly this is because many people don’t know the amount of fiber that they need. I like to explain to clients what the health benefits of fiber are, which makes it far easier for them to want to incorporate fiber into their diet.

Many experts agree, and have for generations, that fiber is great for your overall health. Some studies show it can lower your risk for certain disease, including heart disease, and can even lower your risk of certain types of cancer, especially colon cancer. Fiber consumption in the proper amount also helps lower other risk factors tied to diseased states like diabetes, obesity and other disorders of the GI tract, including leaky gut syndrome. Fiber will slow down how quickly food is digested after being consumed. This may mean that you can have enough energy through the day to go to work and be able to survive an after-work fitness class at your gym, the one you’ve been avoiding because “you’re too tired”.

Fiber can be further broken down into other classifications:

Functional Fiber

This classification of fiber has specific purposes within the body, including the feeling of being fuller longer, and improved control of insulin secretion, as well as resulting in more stable blood sugar levels. Motility and absorption are also influenced positively by fiber intake, meaning that fiber will help to prevent constipation while working to reduce dietary fat and cholesterol absorption in the gut.

Dietary Fiber

This type of fiber is characterized by those items considered non-digestible in the gut. The sourcing of this type of fiber is derived from the lignins within plants that are consumed. The presence of dietary fiber in (carbohydrate) foods helps to slow digestion, thus reducing their glycemic index and their effect on blood glucose levels.

There are two basic types of dietary fiber: soluble and insoluble fiber. The best sources of fiber include beans, fruits, vegetables and tree nuts. It’s important to incorporate some of these items into every meal.

Total Fiber

This is simply the total of both functional fiber and dietary fiber, combined.

Fiber is important. And it’s far too easy to incorporate fiber into your daily diet to not do it. So now we can stop snickering at grandma for drinking her glass of prune juice every day, because everybody poops! Sadly, many individuals with food intolerance’s like gluten and lactose, and those suffering leaky gut syndrome have a hard time doing this, either suffering from constipation or diarrhea.

The Glycemic Index

You’ve probably heard of the glycemic index, but like fiber and carbs, you probably don’t know exactly what it is.

In the body, the rise of change in blood glucose levels is called the glycemic response and is defined as being determined after consuming any food containing 50g of carbohydrates. Then, this number is compared to the glycemic response of a standard carbohydrate of known value, serving as the reference point and is the comparative index. In nutrition, it is typical to consider white bread as the standard carb to reference due to it having a glycemic index value of 100.

Higher glycemic loads (carbs) enter into the bloodstream very quickly upon consumption and are therefore available for use both during and after exercise, as the body seeks to replenish glucose quickly. During other times, when you are not in the middle of a workout (or recovering from one), the main type of carbs ranked by lower glycemic values should then be consumed, as to best control blood sugar and insulin levels. It should make sense that foods lower on the glycemic index are also higher in fiber, as you now know that slows the glycemic response.

Whew. That was a flashback to high school biology. 

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