Truth About Carbs

We have all heard or read about the "evils" of carbs. We are told that carbs are a major cause of obesity and poor health. Fad diets have been created around the concept of "low carb" or "no carb" and so-called experts tell us that following those diets will help us lose weight and become healthier. Is this really true?

Unfortunately, a lot of this information is just hype and not based on scientific fact. Carbohydrates, often shortened to "carbs", are a type of biomolecule (other types that are the major components of food are protein and fats/lipids). The human body creates energy from the food we consume - and the body's preferred source of energy is carbohydrates. Carbs provide nutrition that we cannot obtain from either protein or fats, and certain cells in the body (especially in the central nervous system) rely solely on carbs to function correctly. Eliminating or reducing carbs from the diet will actually have a negative impact on overall heath. Furthermore, a special type of carb is known as dietary fibre - which helps regulate digestion and has health benefits including lowering the risk of heart disease and certain types of cancer. Carbs and dietary fibre also help to maintain the feeling of "fullness" or satiety after we eat, so we are less likely to snack between meals. Those individuals who are looking to increase muscle mass need to be aware that carbs are "protein sparing" - this means that the human body burns carbs for energy needs and utilizes the protein we eat to help build muscle mass and repair tissue. Without a sufficient amount of carbs in our diet, the body will be forced to get its energy from other sources including protein, thus lowering the amount of protein available to build muscle.

You might have also heard about the glycemic index - this measures the impact that a particular food has on blood sugar and insulin release when the food is eaten by itself (on an empty stomach). The greater the impact, the higher the glycemic index - which is considered to be a bad thing, since wide fluctuations in blood sugar and insulin levels can be related to an increase in the body's fat storage. The problem with this is that we rarely eat food items separately, each on an empty stomach - instead our meals combine different types of food at one time. The combination of different foods eaten at the same time alters the glycemic index of the individual foods. Nonetheless, it is better to select carbs that are lower on the glycemic index. High glycemic index carbs (that have a high impact on blood sugar and insulin) include foods such as sugar, honey, potatoes, white rice and white bread. Carbs that have a lower glycemic index include whole wheat bread, brown rice, sweet potatoes, beans, lentils, and most fruits and vegetables. Overall, when selecting carbs to include in your diet, it is better to select lower glycemic index options - for example, choose brown rice instead of white rice, whole wheat/grain bread instead of white bread, whole wheat pasta instead of white/plain pasta, sweet potatoes instead of white potatoes, etc.

So do those "low carb" or "no carb" diets really work? In the short run, cutting out or restricting the carbs in your diet will naturally cause a decrease in your total caloric intake (unless you increase the amount of protein and fat) - so this lowering of calories may cause you to lose weight but it would be better to lower your caloric intake of all biomolecules (carbs, protein and fats) proportionately, not just cutting one type. When carbs are cut or lowered in the diet, this decreases the body's store of glycogen (glycogen is created from carbs and stored in the muscles and liver to provide energy when the body needs it) - and when glycogen levels fall this removes water from the body as well. Thus, the majority of the "weight" loss that people notice when they go on a "low carb" or "no carb" diet is just water loss and not fat loss. As discussed above, over the long run, this kind of diet is not a good idea since it deprives the body of necessary nutrients and energy from carbs, which are vital for proper health and the ability to perform physical activity.

As a general guideline, 50-70% of the calories that we consume on a daily basis should come from carbohydrates. Your trainer can give you general information and guidelines on healthy eating, and for specific diet plans you should consult a registered dietitian/nutritionist.