Good vs. Bad Carbs / What and Why?
You have all heard about good vs. bad carbohydrates, but what does that really mean? Carbohydrates are foods that our bodies use as a fuel source by digesting them down into the simple sugar known as glucose. But what does digesting them down really mean? This is what starts to explain the difference between good and bad carbs. All carbs are many glucose molecules joined together. Some carbs are just a few joined together and some are very very many. One glucose molecule is known as a monosacharide, and two is a disacharide. Three or more joined together is known as a complex carbohydrate, which is what we typically know as the good carbs. This is because the during the digestive process, if our body absorbs glucose (or sugar) from the GI tract into the blood slowly, there is a very low insulin response and our body functions much better.
If you eat simple sugars, glucose is absorbed into the blood stream very quickly and this causes a quick and large release of insulin from the pancreas. Done time and time again, day after day, this is very bad for the body causing obesity, high cholesterol, and heart disease. When you eat a complex carbohydrate, such as vegetables, or oatmeal, the digestive process takes much longer to break them down into single glucose molecules, simply because of the complexity of their structure. A good carb will be 100s or even 1000s of glucose molecules joined together, and some with fiber mixed into the structure, making is more difficult for the body to digest, causing one glucose molecule at a time to be slowly released into the blood stream. This causes a very slow absorption of glucose into the blood stream and therefore a very mild and appropriate insulin response. This allows for prolonged stable blood sugars and will allow the body to burn fat all day long for fuel, as well as what you are eating. Good sources of complex carbs are vegetables, oats, whole grain wheat, nuts, or anything with lots of dietary fiber. If you are interested, do a google search for the glycemic index, and see what food rate very low. Low ratings mean that those carbs are absorbed slowly and cause a lower insulin response. Also, eating protein during a meal can keep insulin levels lower.
If you are interested in storing glucose, please keep reading. Glucose is stored in the liver and muscles as glycogen, for later use. The body can store about 7g of glycogen for every pound of body weight. Eating complex carbs causes a slow release of glucose into the blood stream and at a slow rate, the glucose will be taken up by the liver or muscle and stored as glycogen. If too much glucose is released into the blood stream, such as by eating too much simple sugars at one time, the glucose cannot be taken up by the liver and muscle that quickly and will be stored as fat by the body. So carbing up by eating a plateful of pasta the night before a marathon does nothing for storing carbs for the run. Sorry.
This is a very complex topic so if you have any questions for clarification, please email back and let me know.