What is the Glycemic Index?
Glycemic index (GI) is a value that indicates how carbohydrates of specific foods affect the blood sugar level. GI represents the increase of the blood sugar level two hours after eating. In short, GI shows how quickly or slowly the blood sugar rises two hours after consuming a particular carbohydrate. It is a fairly new way of analyzing food that goes beyond the conventional methods of carbohydrate analysis in their unconsumed state. Instead, it measures the actual impacts of these carbs after consumption.
The glycemic index approach ranks the foods on a scale of the high, medium, or low based on the glycemic index effects on blood glucose. Foods that have low glycemic index are slow to release glucose but do so in a steady manner. Those on the higher GI scale tend to release glucose more rapidly. Generally, foods with a higher glycemic index are best for energy recovery after intense exercises. The higher scale carbs can also be applied to offset hypoglycemia - insufficiency of glucose. On the contrary, low glycemic foods are known to foster excess weight since most of them get stored in the body as excess carbs.
Since the high GI foods are known to restore lost energy quickly, most athletes or long distance runners do prefer them. The story is different for diabetic individuals. People with early or full-blown diabetes have to work with low GI foods. This is because their bodies do have a challenge of producing irregular or insufficient levels of insulin. Thus, they tend to have excess sugar in their blood. Therefore, to avoid blood sugar spikes, for type 1 diabetes, individuals have to train their bodies by avoiding high GI food. The steady and slow release of sugar by the low-glycemic foods is important for maintaining the blood glucose.
Having described the glycemic index above, what if you want to know the extent with which certain carbs will raise your blood glucose? Can the glycemic index tell that? Of course, no. And that is where the glycemic load comes in. It is a measure that gives a more accurate insight into the extent to which certain amounts of carbohydrates will increase your blood sugar.
To obtain the overall effect of the carbs on the sugar level, we need to know how fast the carb will raise the blood glucose as well as the amount of glucose it will release. The glycemic load will, therefore, provide a complete analysis of the effect of the carbs per serving; which is more accurate and reliable compared to the glycemic index. Hence, glycemic load is a better measure than the glycemic index.
To measure the glycemic load, you will need to multiply the number of carbohydrates (without fiber) in grams per serving by the GI then you divide by 100. A glycemic index of 20 and above is considered high while 10 and below is considered low. Take, for example, the glycemic load of a watermelon that has a GI of 80 is only 5 in its serving. This justifies the fact that glycemic load provides more relevant and precise results than the GI.
Can carbs with the same GI have different impacts on blood sugar?
Yes, they can! Surprising, right? Due to the different unique characteristics, carbohydrates which have the same amounts of starch (supposedly the same GI) have been observed to have different impacts on the blood glucose level. The differences in their chain compositions and structures can explain this deviation. For instance, those that allow more surface area to be exposed to the salivary enzymes and the other digestive juices tend to have a higher GI because of the high level of glucose release.
The methods of cooking have also been known to alter the carbs GI levels. Most legumes do have fairly resistant cell structures that could protect the starch inside their cells from being broken down. This way, unless these legumes are overcooked or ground, they will most likely release their glucose slower than expected and consequently have a lower GI.
• Glycemic Index indicates how carbohydrates in specific foods affect the blood sugar level
• Glycemic Load provides a complete analysis of the effect of the carbs per serving
• Carbohydrates with the same Glycemic Index have different impacts on blood sugar.