What is the glycemic index?
Surely you have proven it on many occasions: some foods raise blood glucose faster than others.This is something that is very clear in the case of the treatment of hypoglycemia, as foods that contain a high proportion of sugars such as juices or sugary soft drinks are chosen.These are those that increase blood glucose faster.
On the other hand, there are more doubts when it comes to the foods that are included in the usual meals of the day.Are there differences between a plate of macaroni or one of rice?Do some fruits upload glycemia faster than others?
To help classify food according to the speed with which they raise blood glucose, the concept of glycemic index (IG) has been created more than 30 years ago.It is a laboratory test, carried out in volunteers who do not have diabetes.In this test, the glycemia values are obtained every 15 minutes after the intake of a certain food and are compared with those obtained by performing the same test with the same amount of glucose.
See attached picture: glycemia curves obtained during the 2 hours after the intake of a certain food (orange) and glucose (blue color).The area of the curve obtained for that food with that of glucose is compared.
With these data, the glycemic index tables are made, where we can compare some foods with others according to the speed with which they raise blood glucose.Attached you can find a table with the glycemic index of some of the most common foods
Values: more than 70: High glycemic index;69-55: Moderate glycemic index;Less than 54: low glycemic index.
Is it important to know the glycemic index of food?
It should be taken into account that the glycemic index values of food are only an orientation data.They help predict the glycemic response to some foods and avoid some hyperglycemia after meals, only replacing high glucemic index foods with others of moderate or low index.However, there is still much to investigate the glycemic index.If tables are made by different authors, certain differences between glycemic index values of the same food can be found.This is because there is great variability between the physiological processes of some and other people, because not everyone digests, absorbs and metabolizes food at the same speed.
In addition, at the main meals of the day it is usual to mix some foods with others, which sometimes is difficult to know what will be the resulting glycemic index of, for example, mix vegetables with potato, fish and a piece of fruit.
Can I modify the glycemic index of my meals?
Over the years it has been thought that foods that raise blood glucose more rapidly were those composed of sugars (also called carbohydrates called simple or simple).It was thought that being simple molecules do not need digestion to be absorbed in the intestine and, therefore, would pass to the blood faster than those foods composed of complex carbohydrates such as rice, pasta or flours in general, as they would need a longDigestion process before being absorbed.
We currently know that there are other factors that have a great influence on absorption speed and, therefore, on the glycemic index.Foods rich in fats or fiber are digested more slowly, so they also produce an increase in slower blood glucose.For example, a food very rich in sugars such as ice cream has a low glycemic index, as it also contains a large amount of fat.The same happens with foodrich in fiber.Thus, whole grains have a lower glycemic index than refined cereals.Cases of pizza or lentils are very popular.They are dishes high in carbohydrates but also with a large number of fats (pizza) or fiber (legumes).Its absorption is extraordinarily slow, to the point that in many cases it is recommended to put the fast insulin after eating them (not before) because it is possible that insulin acts long before the food reaches the blood.
But can we do something in our cuisine to endentize food absorption?The answer is yes.In addition to preferably choosing fiber foods, we must also know that food cooking changes its absorption speed.For example, a plate of pasta is absorbed more slowly than very cooked.We also know that liquid or very chopped foods are absorbed faster than those others less elaborate.For example, it will be more under the glycemic index of a piece of fruit than of a juice.