Introduction:
The Glycemic index is a system of assigning a number to carbohydrate-rich foods according to their tendency to increase the blood sugar level in the body. The Glycemic index is not a diet plan but can be used to calculate calories and plan a diet according to the carbohydrate levels of different food items. According to the glycemic index, the diet plan helps to lose weight or prevent chronic diseases related to obesity, such as diabetes and cardiovascular diseases.
What Is a Glycemic Index?
The glycemic index principle was initially developed as a strategy for regulating and guiding food calories for people who have diabetes. The database for the glycemic index is maintained by Sydney University Glycemic Index Research Services in Australia.
How to Calculate the Glycemic Index of a Food Item?
A health volunteer is given a test food that provides 50 grams of carbohydrates and food, which is either white bread or pure glucose, that will provide the same proportion of carbohydrates on different days. Blood samples are taken before eating and at regular intervals after a few hours of eating to determine the glucose concentration. The glycemic index is calculated under the cumulative curve of glucose (iAUC) after consuming test food, divided by the corresponding iAUC after finishing pure glucose or white bread. The value is then multiplied by 100, which gives a percentage.
What Are Carbohydrates?
Carbohydrates are a nutrient in food's three primary forms: sugars, starches, and fibers. Whenever a person consumes anything with carbohydrates, the body breaks down the sugar and starches into a simple sugar known as glucose. Different food items have different proportions of carbohydrates which differ in regulating the sugar content in the blood.
What Are Different Glycemic Index Values?
As mentioned, the glycemic index value depends upon the amount of sugar a food item can raise in the blood.
Glycemic index values are generally divided into three categories:
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Low glycemic index: 1 to 55.
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Medium glycemic index: 56 to 69.
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High glycemic index: 70 to higher.
What Are the Limitations of the Glycemic Index?
The glycemic index values did not reflect the likely quantity of any food item. For example, in the case of watermelon, which has very few digestible carbohydrates, the glycemic index value is 80. This means that a person needs to eat a large amount of watermelon to make it to value 80 of the glycemic index. Thus a better solution was figured out, and a numerical value known as the glycemic load was given to the change in glucose levels when a standard serving of food is consumed. For example, a two-thirds cup or 80 grams of carrot contains a glycemic load value of 2.
The glycemic load values are categorized as follows:
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Low glycemic load- 1 to 10.
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Medium glycemic load- 11 to 19.
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High glycemic load- 20 or more.
The Glycemic index does not give any information about the food; for example, in the case of milk which has a glycemic index value of 31 and glycemic load value of 4 in a serving of 250ml. The glycemic index value indicates milk to be healthy for intake, but milk has a high-fat content, making it unsuitable for weight loss. Food's glycemic index value also depends on several other factors, such as food preparation, processing, or other food items consumed. Thus the glycemic index value may vary from the same food items and make it questionable to rely on.
What Is the Glycemic Index Value for Different Food Items?
Food items with low, medium or high glycemic index values are:
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Low Glycemic Index Value: Most fruits include raw carrots, chickpeas, kidney beans, breakfast cereals, and green vegetables.
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Medium Glycemic Index Value: Sweetcorn, raw pineapples, bananas, oats, breakfast cereals, raisins, oat bran bread, or rye bread.
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High Glycemic Index Value: White bread, white rice, and potatoes.
What Are the Benefits of the Glycemic Index on Health?
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Weight Loss: Food items with low or medium glycemic index help lose weight and control obesity.
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Control Blood Glucose Levels: Carbohydrate is the primary nutrient that affects blood sugar levels. An increase in blood sugar levels can lead to diseases such as diabetes. Consumption of a low glycemic index diet helps to control diabetes.
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Cholesterol: Consumption of a low glycemic index diet helps lower total cholesterol and reduces low-density lipoproteins (bad cholesterol).
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Studies have stated that a low glycemic index diet affects appetite control. It is believed that high glycemic index food causes a rapid increase in blood glucose, leading to fast insulin response and a return to feeling hungry. However, low glycemic index foods delay the feeling of hunger. The clinical investigation of this study has shown mixed reactions.
Conclusion:
The Glycemic index value is the number of changes in blood glucose levels due to the consumption of carbohydrate-rich food. Different carbohydrate foods have different glycemic index values, which affects blood glucose levels in different proportions. The glycemic index value varies for the same food item depending on its quantity, so a new deal was developed known as glycemic load. It is the value of changes in glucose levels on the consumption of food according to its quantity. The Glycemic index helps plan a diet effectively in controlling obesity, diabetes, and cholesterol and helps in weight loss.
