With respect to the latter, there is a belief that you can help us control it. But it’s true? What is this statement based on? Today we review what we know about these values and their usefulness (or lack thereof) when it comes to eliminating fats.
What is the glycemic index?
We know as glycemic index, or GI, of a food at a value related to glycemia, that is, the ability of a food to raise the amount of blood sugar . These calculations are made by comparing the amount of food with the intake of pure glucose, which is the substance with maximum (and reference) value.
The GI is an indication of the type of carbohydrates contained in a food. This is because the carbohydrates are, in fact, very diverse in nature. That means that not everyone is metabolized in the same way. Some are longer chain, others are indigestible, such as fibers, etc . The GI is used to evaluate the rate of absorption of these carbohydrates, which pass into the blood in the form of glucose, raising the blood glucose level.
What is glycemic load?
The glycemic index has an essential problem: the measurement is made in relative values with respect to 100 grams of glucose , reference, but does not take into account the proportion of existing carbohydrates according to what quantity we eat. To make a better estimate, the glycemic load, or CG, is used. The CG does take into account the size of the ration that we are going to eat of said food, so we can say that it is a somewhat more real measure when it comes to knowing how it will affect our blood sugar to eat that food.
The glycemic load is calculated by dividing its glycemic index by 100 and multiplying it by the amount of grams of hydrates a ration has . This value is more realistic, but it has another important problem: the theory differs greatly from reality because the composition in measured carbohydrates is not corresponding to the bioavailability of the food.
What is the relationship between glycemic index and losing weight?
Some say that foods with low glycemic index help you lose weight. The hypothesis is that by containing sugars of slower metabolism, and being these more complex to catabolize, they spend more energy and time in being assimilated. As a result, they help accumulate less fat, roughly.
But this approach is not true: that they take longer to increase blood glucose, or that they need more enzymatic operations to become glucose does not mean that they provide less energy . On the other hand, we could relate the control of blood glucose peaks with weight loss.
However, this issue is also very complex, and we cannot limit ourselves to making a syllogism that would also be false. To know if the glycemic index is used to lose weight or maintain body weight we must measure it directly. And, in fact, that’s what many researchers have done. What conclusion have they reached?
No, there is no evidence that controlling GI or GC helps to lose weight
Although there are some positive results, these studies have been weak, unorthodox or unclear when it comes to linking GI or GC with weight loss. On the contrary, there are several more robust studies that deny this relationship.
Others have directly verified that this relationship is directly non-existent. Consequently, we have no evidence that allows us to defend the glycemic index or glycemic load as good indicators for losing or maintaining weight. This is due to numerous issues: the bioavailability we were talking about, the extraordinary breadth of the results and endless other things.
These two indicators do not serve to control appetite , not even the level of blood sugar. According to studies, the total amount of carbohydrates in a food is much better indicator of blood glucose levels than the IG or the GC.
What is the purpose of controlling the glycemic index?
Although it has proved useless in weight control, there are other indicators for which there is scientific evidence of utility. We talk, in particular, about cholesterol. There are many studies that confirm that foods with a low glycemic index can help to control cholesterol levels.
This relationship could be due to glycemic peaks, not so pronounced, or to general levels. We do not know for sure. However, cholesterol levels can also be controlled through a healthy and balanced diet. Knowing the blood glucose level can help increase its effect.
In general, maintaining attention to glycemic indices does not help much, despite the various claims coming from certain environments: diets, physical trainers or nutritionists. If we want to lose weight, it is much more useful to look for caloric restriction and, of course, healthier lifestyle habits that allow us to maintain adherence.