There’s a lot of buzz going around the word “carbs”, but, what are carbs? Carbs are carbs! What else? Article done… go, read something else. If only it were that simple. Well, to start, carbs — short for carbohydrates — are a group of organic compounds (chemicals that use carbon as the base) made up for carbon, hydrogen and oxygen. They are used as the primary source of energy in the human body. In fact, the other two macronutrients (fats and proteins) would have to be broken down and “reconstituted” into a form of carbs before being used as energy.
Carbs can be broken down into 2 major categories — Simple and Complex. Simple carbohydrates consist of monosaccharides (one “sugar molecule”*) and disaccharides (2 “sugar molecules”) while complex carbs consist of oligosaccharides (3-10 “sugar molecules”) and polysaccharides (more than 10 “sugar molecules”). Common monosaccharides are glucose (found in dried fruits and honey) and fructose (found in fruits and berries). Sucrose (a disaccharide consisting of one glucose molecule and one fructose molecule) is common table sugar. You can find many oligosaccharides in fruits and vegetables. They generally form soluble fibres which are good for gastrointestinal health. The most common polysaccharide is starch. You can find it is rice, flour and ground provisions/root tubers.
So what is the best type to eat? Well, the reality is that although it matters, it matters less than overall caloric intake. However, when one considers how your body stores energy, you should still try to think about your source of carbs as it does make a small difference. Excess energy is stored as fat for long-term use. The body stores a certain limited amount of glycogen (a polysaccharide) for ready access. When you ingest carbs, what isn’t instantly used is first stored as glycogen and then all excess is stored as triglycerides (fat, as stated above). How quickly this happens depends on two things: 1) the thermic effect of food (how much energy is required to digest and absorb food), and 2) the glycaemic index (GI) of the carb (how quickly a particular carbohydrate raises your blood sugar levels to indicate to your body to produce/release more insulin to start storing the energy). The thermic effect reduces the effective caloric content of the food you eat, and therefore delaying the point at which you reach that threshold that determines when your body starts storing fat. This means that the amount of effective calories in a food can be calculated by subtracting the thermic effect from the total calories in the food. The GI is mainly affected by how long it takes to break food down into simple sugars (which are then used to make glycogen). A lower GI means that your blood sugar raises slower than a higher GI (because it takes longer to break down). In general, the shorter chain carbs (simple sugars) have a higher GI and smaller thermic effect than longer chain carbs, so you want to generally aim for complex carbohydrates. This would mean that you end up storing less fat and also stay full longer, thus reducing your overall caloric intake.
Complex Carbs are also great for people who train hard. Muscle is developed (either increase in size and strength or increase in energy capacity) through post-exercise muscle repair. Energy is required for this. Eating complex carbs also ensures a long-term source of energy to facilitate this repair, thus improving overall results.
What this means is that people demonise the wrong foods. People hail fruits (primarily carrying simple carbs) and then avoid bread and rice (primarily consisting of complex carbs). The advantage that fruits have is that they also contain other nutrients, including fibre, which can slow down the digestion/absorption of the sugars. Otherwise, it is advised that people with diabetes limit the amount of fruit they have because of the relatively high GI.
In my next article, I’ll take a closer look at some of the latest health trends when it comes to carbohydrates — processed vs unprocessed vs semi-processed sources of both simple and complex carbohydrates — and we’ll round off with an understanding of the role that carbs play in our life.
*NB: For the purposes of this article, “sugar molecules” refer to monosaccharide units and are assumed to have 6 carbon atoms, although monosaccharides can have anywhere from 5 to 11 carbon atoms in a single “sugar molecule”.