In general, high glycemic carbs create a large, temporary rise in blood sugar (glucose) because they are quickly digested. Low glycemic carbs take longer to digest, thus produce a smaller and slower rise. A rapid rise in blood sugar means:
More insulin is released. A high insulin level promotes a quick storage of sugar in muscle and the liver. It also inhibits the hormone glucagon, which normally tells the body to burn stored fat. Obese people tend to be “sugar burners”– they mainly burn stored glycogen. Their forthcoming meals restore glycogen (especially if high glycemic) and the cycle keeps repeating. Thus, fat stores do not get touched and usually grow larger.
Blood sugar levels then drop quickly, leaving you hungry sooner. Suddenly, the body needs more fuel. But because glucagon is still in short supply, the body does not tap into its fat supply for energy. The inevitable result? Hunger. You will eat again, needlessly, which can lead to increased fat gain over time.
Facts to consider:
Highly processed foods that contain refined sugars (cookies, crackers and corn syrup) usually have a higher glycemic level.
Other factors affecting the glycemic level is whether the food is liquid or solid, raw or cooked, and the amount of fiber it contains.
The more grams of carbohydrate consumed the higher the glycemic response because there is an increased glycemic load. So, one can over-consume even low glycemic foods.
Most people usually eat foods in combination. The fat and protein also consumed at feedings can help lower the overall glycemic level.
Not all simple sugars are high glycemic. Fruit, for instance, contains the simple sugar fructose. Fructose has a slow rate of digestion and absorption and thus a lower glycemic response.
Moderate and high glycemic foods are recommended during and after exercise. Consuming a high glycemic food within 45 minutes after exercise elevates plasma glucose concentrations and facilitates muscle glycogen replenishment. Post-exercise insulin secretion increases protein synthesis by increasing amino acid uptake in the muscles. Insulin also enhances blood flow into muscle, thus facilitating the removal of lactate and carbon dioxide.