Written by Brandon D'Orazio
Edited by Rebecca Payne
The concept of “carbs” has been a huge trend in the health and fitness industry as of late. We’ve seen an explosion of diets that revolve around monitoring your intake of carbohydrates such as “low carb”, keto, paleo, and Whole 30. While we never want to discourage someone from following a plan that works for them, it’s important to be aware of how to fuel your body properly so that you can make informed food choices. So, let’s talk about a much-maligned macronutrient called carbohydrates and how they impact your metabolism.
Your metabolism is a series of chemical reactions within the body that keeps yourself and your cells alive. It its simplest terms, your metabolism is food or drink being placed in the body and turned into energy. For the athletic population, carbohydrates are crucial for your performance. Without carbohydrates you will be more likely to fatigue earlier during sport or prior to the start of something such as practice. This being said, it’s not just athletes who need their carbs. Everyone needs to pull energy from somewhere! Whether you’re an elite athlete or someone who wishes they had time to be more active, carbohydrates fuel you, so understanding their impact on your body is key.
The Glycemic Index and Your Metabolism
Foods that come to mind when we talk about carbs include: breads, pastas, fruits, vegetables, potatoes, and sugars. Customarily, we would view these foods as complex or simple carbohydrates. To illustrate the difference between the two types of carbohydrates, we can view each by the differences in their molecular structure; however, to keep it simple, let’s look at it like this: Your body’s metabolism is like a fire or a wood burning stove. The fire breaks down the paper or wood products thrown into it to create energy in the form of heat. A simple carbohydrate will release all of its energy quickly, comparable to throwing in paper or dried kindling from a tree such as cedar or birch (wood that burns fast!). If this is all you have to keep the fire going, you will need to keep throwing on more and more wood, which will cause a big spike and sudden decrease in the flames. However, throw on a large piece of oak (a dense wood that burns slowly) and the fire will continue to burn for a longer period of time at a more consistent temperature, and it will do it with less wood. In this scenario, complex carbs are like the dense oak wood, because the fire (representing your body) will have a more difficult time breaking down its complex structure, lowering the speed at which energy is released. Fibre is a plant based nutrient that can not be completely broken down within the body (Most dark leafy greens, nuts, seeds, beans & legumes). The human body does not contain the right enzymes to properly break it down which is why you may hear it being referred to as roughage. It helps to aid digestion by keeping everything moving through the intestines before it leaves the body. Fibre will be more commonly found in complex carbohydrates. Most but not all simple sugars will have lower fibre content.
Now that you have a very simple idea of how your body’s metabolism works (also fires) with the digestion of simple and complex carbs into energy, let’s learn about the glycemic index and load; what that really means, and why it is important.
Glycemia is glucose (sugar which is carbohydrates in its most simple form) found in the blood. The glycemic index is a scale used to measure how fast sugar will be broken down and absorbed into energy throughout the body. There are foods with a low glycemic index (think of the oak log on the fire and how the fire reacts to it!), foods that have a moderate glycemic index, and foods with a high glycemic index level (the maple or birch on the fire, HOT and FAST!). This scale was originally used for helping diabetic patients to control their blood level sugar; however, now the fitness and health field has taken it over because it is applicable to everyone from the general population to high performance athletes. The scale measures from 0-100. Any food rated 70 or above is considered a high glycemic index, 55-70 is considered moderate, and anything under 55 is considered to be a low glycemic index. The general public can use this information to control their levels of body fat by eating the appropriate carbohydrates at the right time for their own metabolism. When you eat your carbohydrates, there are factors that can slow their breakdown into energy, such as:
· The size, texture, and ripeness of food (ripe or overripe food will contain a higher glycemic index).
· Presence of fat and protein reduces glycemic index
· Presence of fibre reduces glycemic index
· Presence of fructose (sugar often found in fruit) will provide a lower glycemic index
You may be thinking about what happens when your body is finished digesting carbs. If your body needs carbs, it can be utilized as energy and will remain as glucose, which is sugar in the blood. Another possibility is it can be turned into glycogen, which is how the body stores carbohydrates. Skeletal muscle will store most of your body’s glycogen, followed by your liver. Other small amounts of glycogen can also be stored in your brain tissue, adipose tissue (fat stores), kidneys, and heart. Once your body has replenished its carbohydrates it will store the excess carbohydrates as fats.
When you are trying to pick what foods are appropriate for what time of the day it can get fairly tricky because, yes, you have looked for the right things. You are finishing up a workout or you are sitting at your desk and you have identified the right type of carbohydrate to suit your activity level. Now we need to consider the concept of glycemic load. The load refers to the amount or how many carbs are in your serving size. For example, although an apricot qualifies as a food with a low glycemic index, it would be inadvisable to feast on an unlimited number of apricots because the load is the sum or total amount of sugars your body is digesting. On the flip side of this example, you could have a food with a high glycemic index such as a baked potato, but if you only have a third of it, you will only consume a small amount of carbs resulting in a low glycemic load.
Glycemic load can be expressed in different ways. When you are researching foods and their glycemic load, the nutrition label will tell you what the suggested serving size is. Getting familiar with serving sizes will make it easier to casually keep track of the total amount of carbohydrates you consume. Remember that glycemic load can be expressed by being:
Low glycemic load = 1-10
Medium glycemic load = 11-19
High glycemic load = 20+
If you click here, you can access a PDF file that contains over 100 different common foods eaten by North Americans, and shows their glycemic index, glycemic load, and serving size. This will be a great tool for you to use when trying to plan your meals for the week as well as making sure you are taking care of the details in your own health and nutrition. And remember as you go through this does not mean you have to weigh all of your food exactly, it is more of an idea about awareness and being able to make strategic decisions in your every day life that will be suit you in your sports performance and health and wellness goals!