Glycemic index and glycemic load, what are they and what are they for?

When you want to talk about the amount of carbohydrates that a food contains, the concept of a glycemic index is usually used, which refers to how this food affects our blood glucose when we take it. But it is not a very exact term to say, although it may be practical at first glance.

Another concept that is less known but that is more accurate is the glycemic load, which relates how it affects the amount of sugar that has a food but edible ration. It makes more sense because it is not the same hydrates that there are in 100 grams of food and how it affects us than what is in a ration that we usually eat.

What is the glycemic index and what are its limitations?

The glycemic index (GI) measures how a food affects our blood glucose. That is, the ability of a food to raise the amount of sugar in the blood after it is ingested. The limitation of the glycemic index is that these calculations are made with a quantity of food that contains 50 grams of carbohydrates, in order to compare it with the intake of 50 grams of pure glucose.

In glycemic index tables, the maximum varlor of 100 corresponds to that of glucose . These 50 grams of pure glucose provide a maximum change in blood glucose and, therefore, in the insulin response. If a food approaches 100 in the tables of glycemic index, we estimate then that it will modify the glycaemia in a similar way to what glucose does and vice versa.

• Food with high GI : between 100 and 70.
• Food with average GI : between 69 and 56.
• Food with low GI : 55 or less.

Let’s take a practical example: an apple has a glycemic index of 35. But actually an apple has only 17 grams of carbohydrates , so to calculate its glycemic index were used about three apples (51 grams of hydrates). We do not normally eat three apples at a time, so the impact of the apple on our blood glucose levels will not be exactly what the glycemic index tells us.

In addition, the absorption of the hydrates of a food depends on several factors . Normally we eat several foods at the same time and this affects the absorption of hydrates, unlike how the glycemic index calculations are made, where only that food is eaten. Even the GI of a food can vary from one person to another .

What is glycemic load and what is it for?

It is another measure that relates the hydrates of a food and its impact on blood glucose. Unlike the glycemic index, the glycemic load does take into account the size of the ration we are going to eat from that food, so we can say that it is a somewhat more real measure when it comes to knowing how it will affect our blood glucose eating that food

The glycemic load of a food is calculated by dividing its glycemic index by 100 and multiplying it by the number of grams of hydrates that a ration has. In this way the size of the ration to be ingested is taken into account, something that is noticed when comparing the GI of a food and its glycemic load.

But this measure is not a panacea either, since it only serves if we want to know how a single food affects our blood glucose levels. As it happens with the glycemic index, when we eat we usually mix several foods, with which the concept of glycemic load is blurred and can not be applied one hundred percent.

• Foods with high glycemic load : more than 20.
• Foods with average glycemic load : between 11 and 20.
• Food with low glycemic load : 10 or less.

What must be considered ?

The index data and glycemic load will be useful if we want to know how a single food will affect our blood glucose after eating it . For diabetics, for example, if they have a lowering of sugar it will be useful to know which food will raise their blood glucose more quickly.

Or if we play sports, we will be interested in foods with a high glycemic load at the end of training to recover and replenish glycogen stores. Or low glycemic load foods before training or competing to not have blood glucose peaks.

If we want to know exactly how a certain dish or menu would affect our blood glucose, the only way to know would be to make measurements with a glucometer before and after eating . This is handled very well by diabetics, who based on measurements can intuit and know how they will affect a food or food.

What foods avoid high blood sugar?

If our diet is based on low-index foods and glycemic load, obviously there will not be many peak blood glucose, something that is beneficial for health. And, what are those foods ?. Fruits, vegetables, and protein foods help the blood glucose does not rise suddenly after a meal.

Also, nuts such as walnuts, almonds, pistachios or peanuts , when consumed with foods with high glycemic index make the blood glucose does not rise as much. This, among other reasons, makes it recommended that in each main meal the intake of fruit, vegetables, vegetables and a protein source, in addition to regularly introduce nuts into the diet.