Learning about Carbs
Carbs provide your body with the fuel it needs for physical activity and organ function – so any diet that gives a blanket statement of “Don’t eat carbs” is not only unsustainable, but also unhealthy. Your brain and nervous system relies on a steady stream of glucose, using about 130g/day (about 45% of the recommended daily intake). Instead of choosing no carbs, choose good carbs.
Carbs are built out of sugar molecules, and we have often thought of simple carbs as 1-3 sugar molecules linked together, while complex carbs are made up of 4 or more sugar molecules.
Almost all carbs are broken down by the body in the same way, breaking them down into single sugar molecules, glucose, which are then able to cross into the bloodstream. Your pancreas responds to an increase of glucose by releasing insulin. Insulin then travels and binds to your cells membranes allowing cells to take up glucose from the blood and normalize the levels of sugar in the blood.
Thus, carbs play a role in diabetes, if you swing too far in one direction, continually creating insulin you eventually wear your pancreas out – and get type II diabetes.
There is one carb, however, that is not digestible – fiber. Fiber is unable to be broken down, and thus passes through your system. Soluble fiber binds to LDL and transports it out of the system, lowering your bad cholesterol. Insoluble fiber helps to push food through the intestinal tract.
Choosing good carbs, those that are high in fiber and have a low glycemic index, leads to a healthier body. The glycemic index (GI) of a food is a marker of the effect that a food has on blood glucose levels, with a lower number being preferable (55 or less is considered a low GI food). Common low GI foods include beans, nuts, seeds, most fruits and vegetables and most whole intact grains. High GI foods, ones to steer away from, are things that seem obvious; white bread, cookies, corn flakes, potatoes and pretzels to name a few. Check out an extensive study on the GI of foods worldwide, or see the Harvard study for a nicely compiled table.