Glycemic Index and Glycemic Load: Recommendations for Managing Blood Glucose

Glycemic Index and Glycemic Load

Recommendations for reducing blood glucose levels

Currently, in addition to the Glycemic Index concept, which already has considerable recognition among athletes and people who take care of their diet, the Glycemic Load concept has emerged, which, although not as well known, is also gaining great relevance for healthy eating programs.

What Is the Glycemic Index?

The Glycemic Index (GI) began to be taken into account when, back in the 1980s, it was observed that foods with the same amount of carbohydrates had different effects on blood sugar levels. Thus, the GI was defined to indicate how quickly a food raises blood glucose levels.

Foods with a higher GI raise blood sugar faster than foods with lower glycemic indexes.

The GI is calculated in relation to glucose, which is assigned a GI=100, with foods having a high GI being those greater than 70, those with a medium GI being those between 56 and 69, and those with a low GI being those below 55.

Glycemic Index and Obesity

And why is the GI related to obesity?

The glycemic index has the ability, in certain diets, to impact blood-glucose concentrations and, in certain diets, satiety and appetite. Body weight is influenced by many other factors related to diet and lifestyle, so the GI alone does not determine the potential for obesity.

What Is Glycemic Load?

However, the GI does not take into account that when we eat food, we do not only ingest carbohydrates as happens when we ingest pure glucose, 100% carbohydrate, and therefore how to compare a complete food, which in addition to carbohydrates has proteins, lipids, water, fiber, vitamins, minerals…? For this, the concept of Glycemic Load (GL) appears , which assesses not only the speed at which a food is converted into sugar in the blood but also the amount of carbohydrates in a serving.

The glycemic load is obtained by dividing the GI by 100 and multiplying the result by the available carbohydrate content in a serving in grams.

Glycemic Index vs. Glycemic Load

Thus, we could say that while the GI refers to the speed at which a type of carbohydrate is absorbed and passes into the blood, the glycemic load refers to the overall blood glucose impact of the amount of carbohydrate in a serving. For example, watermelon has a high GI value, yet its glycemic load can be low because it contains relatively little carbohydrate per serving.

How Cooking Can Affect Glycemic Index and Glycemic Load

No food is inherently better or worse than another based on its glycemic index (GI); it all depends on the situation. Furthermore, it’s important to remember that the GI of foods is measured under experimental conditions, after fasting and consuming only that specific food. This is not typical in everyday life, and simply eating different foods or cooking them in different ways can distort the meaning of the GI.

For example, pasta, which has a glycemic index (GI) of less than 50, has a much higher GI if it’s overcooked, unlike when it’s cooked until firm. The same is true for rice; the more overcooked it is, the higher its GI.

Why Can Cooking Change the GI/GL of Pasta?

Pasta is made primarily from semolina flour, a minimally refined flour derived from wheat and therefore composed of complex carbohydrates like starch, which require enzymes to be digested. Cooking pasta allows the enzymes to do their work, meaning less energy is needed to digest it. For this reason, pasta must be slightly firm, or “al dente”, to be ready to eat and produce a slow release of glucose into the bloodstream. → The longer pasta is cooked, the higher its GI can be.

How the Type of Food Can Affect Glycemic Index

It should also be noted that the GI of the same food can vary considerably depending on the type chosen, for example, with rice:

Recommendations to Lower the Glycemic Index

Some recommendations to lower the glycemic index:

• Seasoning: Highly acidic foods slow down digestion. Adding vinegar or lemon juice to meals may affect the glycemic response. For this same reason, pickled foods are sometimes included in meals.
• Eat them raw, if possible: Uncooked fruits and vegetables can have a different glycemic response than cooked foods. Whole grains have a lower GI than their flours. Pasta and rice have a lower GI; the less they are cooked.
• Opt for whole-grain products: The less refined the food, the more fibre it contains and the slower the digestion and release of glucose into the bloodstream, thus lowering the glycemic index.
• Choose foods with fibre: The higher the fibre content, the lower the glycemic index (GI) usually is compared to the same food without fibre. Legumes and nuts are high-fibre foods with a low GI. Choose whole-grain bread over white bread, eat apples with the peel instead of peeled, and choose muesli-type cereals over cornflakes.
• Mix foods appropriately: The foods eaten in the same meal can affect the overall glycemic response. Fats and proteins slow down digestion, so carbohydrates combined with fatty or protein-rich foods tend to have a lower GI.

Conclusion

The GI and GL can be useful to theorise how each food and its standard serving size can impact blood glucose levels. The GI compares the rate at which each individual food containing carbohydrates would affect blood glucose levels. The GL also takes into account the calorie number of carbohydrates present in each serving. For example, the effect of cooking the food, the types of food, the fibre content of each food, and the combination of various foods within each meal can all influence blood glucose levels. Using the concept of the GL combined with a balanced diet can be beneficial to maintaining blood glucose levels.

Also Read: Know About Fasting Plasma Glucose Test: Uses, Procedure, And Results