For some time Glycemic Index (GI) has been touted as the possible cure-all for weight loss by many nutritionists. Based on this index carbohydrate foods have been categorized into good and bad with respect to weight and overall health. To lose weight people are told to eat good carbohydrates and avoid the bad ones. This article looks at what is glycemic index, how does it work and why should dieters pay attention to it.
What Is Glycemic Index (GI)
Our bodies convert different types of carbohydrates to blood glucose at different rates. The rate of conversion seems to be specific for each carb. Carbohydrates that quickly breakdown and release glucose into the blood stream are called high glycemic index (high GI). Carbohydrates that have a low glycemic index (low GI) are broken down slowly and release glucose into the bloodstream in a slow and steady fashion.
In other words, glycemic index (GI) is a value that assesses the effects of carbohydrates (carbs) on glucose levels in the bloodstream.
How Does Glycemic Index (GI) Work
Every cell in our body requires fuel for energy. Glucose is the primary source of energy for brain cells and the cells of the nervous system. The rest of the body cells also depend on glucose for energy to some extent. To sustain life and proper functioning of our body glucose must always be present in the blood stream at a certain level. This is called glycemia level and glucose balance (homeostasis) must always be maintained.
The homeostatic balance of glucose is maintained by pancreas and two of its hormones: insulin and glucagon. Scientifically, the process is very complex. Briefly, the pancreas and its hormones work together to ensure that the glycemia levels remain normal at all times.
Insulin helps to eliminate glucose from the bloodstream. It helps to move glucose into the cells, either for energy or to store it elsewhere in the body including the fat cells. In other words, insulin is essential for regulating carbohydrate and fat metabolism in the body and it also facilitates storing of excess carbohydrate calories as fat.
When glycemic levels are high, high levels of insulin develop. High insulin levels are known to suppress two other important hormones: glucagon and human growth hormone. These hormones, among other, regulate fat burning and they promote muscle development, respectively. When there is an excess of glucose in blood, by inhibiting these two hormones, insulin promotes fat formation and also inhibits the body’s ability to lose that fat.
Why Is Glycemic Index (GI) Of Foods (Carbohydrates)Important
After carbohydrates break down they release glucose into our bloodstream. Low glycemic (low GI) carbohydrates break down slowly and release glucose gradually into the blood. This helps keep the insulin balanced and it is exactly what you want if you wish to lose weight.
High glycemic (high GI) carbohydrates break down fast and release of glucose is also sudden and fast. This creates a havoc with respect to the insulin balance and causes a state called hyperglycemia (high blood glucose). This is typically what you get when you eat sugar and pastries (as well as other high GI foods).
Research suggests that understanding the glycemic index (GI) of the carbohydrate foods we consume will help individuals control the blood glucose levels and subsequently control the havoc created by high glycemia as described above. It is currently believed that consumption of high GI foods may be detrimental to one’s health and likely cause weight gain. It is also believed that low GI diet may prevent diabetes and heart disease as well as other diseases including certain cancers. In addition, low GI diet is thought to prevent obesity and help people to lose weight.
Table Of High And Low Glycemic Index Foods
*adapted from: Eat Yourself Slim by Michel Montignac
In summary, whether the glycemic index (GI) of carbohydrates is the ultimate driving force for losing weight permanently is still debatable both, from the scientific and a practical point of view. For the time being, based on all the evidence, it would be wise to embrace this view. Many nutritionists and health care professionals already recommend that you remove high glycemic index (GI) foods and incorporate low GI foods in your diet if overall good health and permanent weight loss are your goals.