Breaking it Down: Carbohydrates

What is a calorie? What is metabolism? How do the foods we eat break down into the calories that feed our metabolism?

The Miriam Webster dictionary defines a calorie as, “a unit equivalent to the large calorie expressing the heat-producing or energy-producing value in food when oxidized in the body”, in which a ‘large calorie’ is “the amount of heat required to raise the temperature of one kilogram of water one degrees Celsius”.

So, food calories feed and fuel our metabolism, which in turn keeps all of our organs running optimally. BUT, not all calories are created equally. The key is to get calories from good food to fuel our daily activities, maintain and/or lose weight, and stay healthy and energized throughout the day! Knowing where these good calories are in the carbohydrate, protein and fat choices we make, and better still, understanding how these different calories break down to do what we need to do throughout our day, will help you stay on track in always choosing the right ones!

Understanding the break down of each of the three macronutrients— carbohydrate, protein and fat— will allow you to make little adjustments in these areas, as necessary. Let’s look at carbohydrates first. Understand their importance in the diet and for our bodies, and which ones to choose throughout the day. Identify where you may be able to make better choices and then make one little change at a time. When it comes to adopting healthy lifelong behaviours, we know we can’t try to change everything at once. Little steps will lead you to the bigger picture, so do just that!

Carbohydrates serve many different functions in our bodies, including helping to fuel our central nervous system and brain, to fueling our muscles for the different activities they go through on a daily basis.

Carbohydrates come from many different food sources, and can be classified as sweet or starchy.  These include fruits, vegetables, whole grain products and dairy products. Of course, these are the most natural, less processed carbohydrate-type foods which we need to choose more often. Baked goods, sweets, confectionary and processed snacks also contain carbohydrate, but these types of carbohydrates should be eaten much less often, and serve a particular purpose for their consumption. Most of the carbohydrate used to make these “processed” items are highly refined, which means the majority of the nutrition has been stripped away leaving “empty calories”, not affecting our metabolism in a favourable way.

So what is a carbohydrate? Carbohydrates can, most easily, be thought of as simple or complex. This has been discussed many times throughout previous articles, but let’s break it down even further. Simple carbs are just that, simple to break down, smaller in chemical structure, and [often] quicker to get into our bloodstream. Monosaccharides are “one sugar” molecules, glucose or fructose, whereas disacchardines are “two sugar” molecules. The main dissacharides being sucrose (glucose and fructose molecule attached), maltose (2 glucose molecules attached) or lactose (glucose and galactose molecules attached). Of all of these chemical names, it is important to know that glucose is the primary fuel our bodies are able to use for energy (when needed), so the liver must convert any non-glucose products to glucose first before our cells and muscles can use that food source. If our body doesn’t require the glucose at the time it is ingested and digested, the breakdown product is stored in either the muscle or liver as glycogen, OR as fat (if our glycogen stores are full already).

Complex carbohydrates break down slower, because they are made of many simple carbohydrates linked together by a number of chemical bonds. IF choosing the right complex carbohydrates, there is often more fibre, resulting in a more gradual release of glucose into the bloodstream, ultimately making blood sugars more stable. In simplest terms, the more chains and branches a carbohydrate has, the more complex it is, and the more slowly it is broken down. Some carbohydrates are so complex that the body cannot digest them, and they pass along the digestive tract to be excreted. This is fibre. The non-digestible component of carbohydrate which will be discussed in the next part of this series!

Although carbohydrates tend to get a bad rap, they are an important part of the diet, and for athletes in particular, are required to fuel any activity effectively and safely. For everyone, the TYPE of carbohydrate to choose is key: choose carbohydrate from foods such as fruits, vegetables, whole grains and dairy more often as opposed to carbohydrate from highly processed, low-fibre foods. For very active individuals, glycogen (the stored form of carbohydrate), is the first choice of fuel our bodies prefer to use, from short bursts of exercise to weight training-type regimes. During the first few minutes of any exercise, it is the glycogen stores which the body taps into first. For longer, slower (i.e. lower-intensity) periods of exercise, our bodies will start to breakdown fat, BUT a source of carbohydrate is still required in order for this to happen as our bodies were designed to make it happen.

Some athletes may restrict carbohydrate too much, and increase their protein consumption. While it is important to include an adequate source of protein in the diet, to promote satiety at snacks and meals, if you are a highly active individual, you need to ensure it is the carbohydrate that is primarily fueling your activity. If our bodies do not have enough carbohydrate to help keep us moving, the break-down systems will shift to begin breaking down protein into glucose for energy. We have to remember that protein helps to build muscle, bone, skin, hair, teeth and repair tissue as its primary functions. So, if our body reverts to breaking down protein for energy, it may not have adequate amounts to carry out the repair and maintenance processes it is needed for throughout the body. More importantly to note is the added stress your kidneys take for having to work harder to rid your body of the breakdown products from the protein which do not provide energy, and are therefore not required by our bodies at the particular time. More on protein will also follow in this series!

So, know where your carbohydrate intake is for breakfast, lunch, dinner and snacks. Whether it comes from fruits, [some] vegetables, whole grains, or some milk products. Choosing a balance is key, and making sure your complex carbohydrates are included in your evening meals will help your blood sugars remain stable throughout the night and not wake up famished! Make smart choices to fuel your workouts, and more importantly, to replenish your stores following a workout so that your body has substance to perform all of its necessary functions properly!  These particular amounts are quite individual, and it is always best to speak to a Registered Dietitian or Physician for specific guidance on your individual needs.