Why do we need carbohydrates?

Generally, I believe in moderation as part of a healthy, balanced diet. I also believe in focusing on whole foods and limiting processed foods when possible. A healthy, balanced diet includes carbohydrates, or “carbs”. We’ll address what “carbs” are below, but they include things like grains, but also…. SUGAR! Sugar, in moderation (including my favourite form… Cadbury’s chocolate (Whole Fruit and Nut milk chocolate bar if I can get it) can form part of a balanced diet. Carbs have earned a bit of a bad reputation, but they are an important part of a healthy diet.

So let’s dive right in to those big, scary CARBS!!! There are three macronutrients – carbs, protein and fat. Later blogs will address protein and fat, but today we’re focusing on carbs. Carbs probably have the worst reputation of the three macronutrients.  Twenty years ago, the main enemy was fat, which I’m sure will take the front seat again in time as there seems to be a cycle in diet themes.

Carbs have been vilified for quite a while. A quick search of “carb diet” can lead into a vortex of low-carb or carb-free diets from both reputable and less reputable sources.  

When trying to sort through all the carb information out there, it is important to remember that just because a low-carb or carb-free diet worked for someone who posted about it or wrote a book about it, does not mean it will work for you.  As a dietitian who has worked in clinical nutrition for over 10 years, one thing I have learned without a doubt, is that everyone is different. What works for one individual may not work for someone else – even if they have exact same medical history.  Figuring out what works for you is often trial and error which can be very confusing and frustrating. Help from your family doctor and a Registered Dietitian can help you navigate all of the options to find out what is best for you. Please see my blog post “Why do we even need Dietitians” for more on this topic.

Back to carbs, I am not suggesting that low-carb diets are unhealthy, but if we better understand what carbs are and what they do for our bodies, we can make better choices when sorting through the endless amount of dietary information available.

What is a Carbohydrate?

Let’s start with the basics. The basic chemical definition of a carbohydrate is that carbs are neutral compounds of carbon, hydrogen and oxygen.  These carbohydrate compounds can be found in simple forms of sugars and more complex forms of starches and fibres. How the body breaks down and uses carbs depends on the type of carb and how it is consumed. Ultimately, all carbohydrates are eventually broken down into simple sugars (often glucose) that the body can then use for energy. These sugars are absorbed into the bloodstream through the digestive system, which causes the level of sugar in your blood to rise.  As a result, the pancreas releases insulin. Insulin is a hormone needed to move sugar from your blood into your cells, where it is used for energy.

Types of Carbs

Simple carbs (i.e., sugar) are naturally found in fresh fruit and some vegetables, milk and milk products. Carbs can also be added sugars in concentrated form, such as honey, corn syrup, maple syrup and white/brown sugar. Simple sugars are digested and absorbed very quickly, providing a fast source of energy. Because they provide a quick source of energy, people often feel hungry again quickly after consuming simply sugars, and may even feel tired. As part of a healthy lifestyle, it is recommended that people limit the amount of added sugars in their diets and eat more naturally-occurring sugars.

As mentioned above, starches and fibre are considered complex carbohydrates. Some examples of foods that include complex carbs are bread products, crackers, oats, barley, quinoa, cereal, pasta, rice as well as some fruit and veggies. As with simple carbs, not all complex carbs are equally healthy.  White flour and white rice are considered refined grains and are typically more processed which can remove some of the beneficial nutrients and fibre compared to whole grain products. Whole grains, like brown rice, are unrefined grains and are more beneficial. This is because more of the nutrition and fibre remains because they aren’t processed as much. A whole grain is, as it sounds, whole, meaning the grain is in its whole form or ground into a flour when still whole. This includes the seed which contains 3 main parts – the bran, the germ and the endosperm. These parts together can provide higher sources of fibre and other important nutrients (whereas white flour, as an example excludes the bran and the germ).

In addition to providing more nutrients, whole grains provide added fibre, which provides longer satiety. Satiety is the body’s mechanism for identifying a feeling of being full. Complex carbs provide satiety and slow down the breakdown of food, giving people energy over a longer period of time. In a later post, I will talk about fibre in more details, including both soluble and insoluble fibre.

What do Carbs do?

Other than provide a source of energy, carbs have other important jobs such as:

  • providing stored energy in the form of glycogen in your liver and muscles. Liver glycogen helps to maintain a balanced blood sugar level, while muscle glycogen is used as fuel for muscles during activity.
  • helping the digestion and absorption of nutrients
  • Helping to keep our bowels regular
  • providing a main source of energy during “fight or flight”
  • lowering the risk of heart disease and colon cancer

Health Canada has recently released its updated Food Guide (https://food-guide.canada.ca/en/), which recommends we eat whole grains and limit foods high in sugar. There is no specific guidance for the amount of carbs that should be in our diet; instead, the new Food Guide suggests half of a plate consist of fruit and veggies, one-quarter protein and one-quarter whole grains. Each of these groups contain carbs, including protein foods, such as dairy and legumes, as well as fruit and veggies.

Can you eat too many carbs?

Any excess food eaten above what your body needs can be stored. In the case of carbs, excess is changed into and stored as fat (yes, fat!) which can have  health risks. On the other hand, if you do not have enough carbs, your body turns to other sources for energy, including fat and muscle. Care needs to be taken when restricting carbs in a diet as most people hope to preserve or gain muscle and overall health, not to lose muscle.

Bottom Line

  • Carbs are found in many types of food other than just grains and they have many important roles in our body.
  • Cutting out carbs entirely can be complicated, very restrictive and potentially dangerous if not done correctly. Carbs can form a healthy part of a balanced diet; choosing the healthier carbs (less processed, higher fibre) and not over-indulging will still allow you to enjoy carb-heavy foods.
  • Lastly, we are all different, so the same plan will not work exactly the same for everyone. Talk to a Registered Dietitians to find out what is best for you.

Will I continue to have my small amount of chocolate with a hot cup of tea and not feel guilty or worried? YES! I will just make sure that I do not eat a whole chocolate bar every day.

If you enjoyed this blog and/or found it useful please let me know. Keep an eye out for coming blogs on fibre and protein.

Disclaimer:  The above information is intended for general public education and is not intended to be dietetic advice in any respect or to any person. Use of this information does not make any person a direct client of Tanya Brown, RD for any purpose and no such relationship will exist unless a formal client relationship has been entered into. Please consult your Doctor or a Registered Dietitian for individual recommendations prior to making any dietary or lifestyle changes.


Canada’s Food Guide (https://food-guide.canada.ca/en/)

Mahan and Escott-stump. 2004. Krause’s Food, Nutrition and Diet Therapy, 11th Edition. W.B. Sanders Co.

D. Mul, Kristin I. Stanford et al, Exercise and Regulation of Carbohydrate Metabolism. Prog Mol Biol Transl Sci. 2015;135:17-37. doi: 10.1016/bs.pmbts.2015.07.020. Epub 2015 Aug 20.

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