Glycemic Index (GI) is a measure of how your choice of unconsumed carbohydrates will affect your blood sugar levels two hours after consuming it. Previously, diet plans formulated to control blood sugar analyzed the total amount of carbohydrates in the food. GI takes it further by analyzing the impact of taking foods containing carbohydrates on blood sugar.
In other words, certain foods loaded with carbohydrates such as pasta, which has a low GI, are slowly digested and absorbed by our bodies. As a result, blood glucose and insulin levels fluctuate only slightly.
The opposite is true. Foods with high GI such as soft drinks are quickly digested and metabolized resulting in the rapid rise of blood glucose. This could lead to unstable and undesirable blood sugar levels.
GI ranks foods from a scale of 0-100, where zero is very low and 100 is very high. To help you understand the glycemic index numbers, the American Diabetes Association breaks down food into three categories:
- 55 or less – low/good GI. Examples include fruits and non-starchy vegetables.
- 56-69 – medium GI. Examples in this category are brown rice and whole grain bread.
- 70 and higher – high/bad GI. Examples here include soft drinks, sweets, and processed white bread.
Most packaged foods have GI on the labels and you can also find the glycemic index of most foods on the internet.
Understanding How Glycemic Index Works
Like we mentioned earlier, GI was originally designed to help diabetes patients control their blood sugar. But scientists and nutritionists later adopted the concept and applied it to weight loss diets.
According to Mayo Clinic:
- GI is a tool to help you select healthy foods that will help you lose and maintain weight.
- Glycemic index determines the impact of the food you eat on your blood sugar. Foods with a high GI causes your blood sugar to rise, thereby secreting more insulin which stores the excess energy.
- The index value varies depending on factors like food preparation and your metabolism rate.
Why is Glycemic Index Important?
The GI values offer an insight into the type of carbs you should incorporate in your weight loss diet. Many people on a glycemic index nutrition plan report that they can finally develop a healthy eating strategy and stick to it.
With GI, you don’t need to count calories, weight food, avoid all carbs, or limit the intake of low-GI foods. It offers a flexible eating habit that will leave you fuller for longer, hence helping you achieve your weight loss goals without too many restrictions.
The GI is flexible in that, if you eat a small portion of food with a high GI, you can make up for it by eating a low-GI food throughout the day. For instance, you can enjoy your birthday cake and later eat a serving of broccoli, fish or an apple.
Low glycemic index diets play a huge role in decreasing the risk of diseases including:
- Type 2 diabetes
- Metabolism syndrome
- Some types of cancer such as colon, breast and prostate cancer
- Heart diseases
What is Glycemic Load?
Every time you eat a meal containing carbohydrates, your blood glucose fluctuates. The quality and quantity of carbohydrates you take determine how high it rises. The glycemic index doesn’t tell you exactly how healthy a food is in terms of nutrients.
Glycemic Load (GL) is more accurate and provides a complete analysis of the effects of your carb intake per serving. It’s a better way of comparing the blood glucose levels of the different carbohydrates you eat.
Glycemic load is calculated by multiplying the GI and the carbohydrate content per portion (g) and then diving the result by 100. Let us take an apple for example. It has a GI of 38 and packs 13g of carbohydrates.
GL = 38 x 13/100 = 5.
Like GI, the glycemic load of a food can be classified into three:
- 10 or less – low GL
- 11-19 – medium GL
- 20 or more – high GL
Despite low-GI foods being a healthier choice, you need to eat the servings in moderation. The more of a specific carb you eat, the more your blood sugar is affected.
Factors Affecting Glycemic Index Value
In general, refined and processed foods have a higher GI than natural foods. Additionally, the preparation of the carbohydrates, the fat content, the physical structure, and fiber content affect the GI value. For instance, food with high fiber content slows down the digestion of carbohydrates and, as a result, the conversion of carbohydrates to glucose is slow.
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