The glycemic index measures the ability of a carbohydrate to raise blood sugar relative to a value scale constructed by taking pure glucose as a benchmark. Let’s see how a low glycemic index food contributes to your weight control.
For a long time, it was considered that all carbohydrates, in equal amounts, had the same effect on blood sugar. Until we discover theGlycemic Index food.
The discovery of the glycemic index (GI)
At one time, when they discovered that one of their patients was diabetic, the doctors recommended to the latter not to eat more carbohydrates (fruits, cereals, legumes, etc.), which forced them to exclusion regime almost impossible to follow.
Fortunately, in the mid-1970s, a researcher from Stanford University in the United States (PA Crapo), on the contrary, demonstrated during various experiments that carbohydrates had different effects on blood sugar.
Crapo was therefore the first to show through several studies that diabetics could continue to consume carbohydrates provided that these have a low impact on blood sugar.
His experiments even showed that one could stabilize diabetes, or even reduce it by the only judicious choice of certain carbohydrates.
In 1981, a researcher from the University of Toronto in Canada, David Jenkins, resuming the work of Crapo, developed a prioritization of carbohydrates from their effect on blood sugar by giving each of them a index calculated in relation to glucose pure which was given the value 100.
The index 100 arbitrarily given to glucose actually represents the area of the triangle of the hyperglycemia curve corresponding. For the same quantity of pure carbohydrate (50 g), the glycemic index of the other carbohydrates is thus calculated according to the following formula:
(area of triangle of tested carbohydrate / area of glucose triangle) X 100
The glycemic index is thus all the more raised that the hyperglycemia induced by the tested carbohydrate is high and vice versa.
Why does the low glycemic index food help to lose weight?
Crapo and Jenkins were diabetologists. Their studies on the variation of the glycemic incidence of carbohydrates and the development of the glycemic index table therefore aimed to provide diabetics with better nutritional comfort.
This also made it possible to introduce a new concept in the treatment of diabetes by inviting specialists in this pathology to adjust their therapy accordingly.
However, the least that we can say is that this discovery, at the time, did not raise not much enthusiasm in the small, hushed world of diabetology where, as in many areas of medicine, revolutionary discoveries are always wary.
The concept ofglycemic index therefore remained very embryonic after its development and, even today, more than 25 years later, it is often treated by most diabetologists with the greatest indifference despite all the studies published since on its therapeutic interest.
The classification between fast sugars and slow sugars is wrong!
For a long time, carbohydrates have been classified by nutritionists into two very distinct categories based on what was thought to be their time of assimilation by the body: “Fast sugars” on the one hand and the ” slow sugars ” on the other hand.
Under the heading “fast sugars” (more precisely fast carbohydrates) were included single sugars and double sugars, such as glucose and the sucrose contained in particular in cane or beet sugar.
This denomination was based on the belief that their assimilation was done quickly, soon after ingestion, simply because of the simplicity of their molecule.carbohydrate.
Conversely, we classified in the category of ” slow sugars “ (more exactly slow carbohydrates) all carbohydrates whose molecule is complex (starches, starchy foods) which were thought to release glucose into the body in a way slow and gradual due to the long chemical transformation required to achieve this.
This is how the fruits were considered to be “Fast carbohydrates” (quickly digestible), whereas potatoes and bread were “slow carbohydrates” (slowly digestible).
However, in 1978, the Australian researcher ML Wahlqvist had demonstrated that this belief was totally wrong. Experiments proved in fact that “The complexity of the carbohydrate molecule does not determine the speed with which glucose is released and is assimilated by the body”.
We see in fact that the glycemic peak of all carbohydrates (i.e. their maximum absorption), whether simple or complex and taken in isolation on an empty stomach, occurs in the same time (about half an hour after ingestion).
The speed of carbohydrate assimilation is therefore not specific, from one carbohydrate to another, as has been believed for a long time. It is therefore necessary to study carbohydrates according to the increase in blood sugar that they induce. This is precisely what the concept of the glycemic index does.
The years of controversy
Michelle montignac for his part discovered the concept of the glycemic index in 1980 when he was working in the USA for a multinational pharmaceutical industry.
Still obsessed with being overweight, having suffered from being a obese child, my father was constantly looking for information that could allow me to definitively solve his weight problem.
He therefore took advantage of his advantage of working in a scientific environment to perfect his documentation on the subject.
Even if they were only interested in diabetes, Crapo’s studies published in 1976 called out to him. Because if more than 85% of diabetics are also obese one could hypothesize that the diet developed for the former could possibly have eventual beneficial effects on the latter.
It didn’t cost anything to verify it anyway.
This is how he lost 16 kilos in three months during his stay in America, then an additional 5 kilos in the months that followed by doing, remember, a diabetic diet, which he was not.
He had thus shown that the choice of food, between what he called at the time “the good” and “the bad” carbohydrates was therefore a means effective for weight loss while continuing to eat normally without calorie restriction.
The basic principle of what will become from the publication of his first book in 1986 the Montignac method, was therefore posed.
Criticized but adopted
The immediate success of this first book, which was aimed more particularly at businessmen and especially of the second (“I eat therefore I lose weight”) published in 1987 for the General Public) immediately triggered the nutritionists reviews and others dieticians for whom all carbohydrates were bound to be good.
The greatest professors even stepped up to denounce a imposture in a large article with the evocative title “To put an end to the Montignac method!” »Published in the« Doctor’s Daily »of October 7, 1993.
The article in question in fact denounced the danger of putting in the public domain ” notions ignored by the medical world itself, not validated in their own field, diabetology, and having absolutely nothing to do with weight gain ”.
the Dr Fricker, leader of anti-Montignac concluded, moreover, as he still did for many years afterwards, that “the Montignac diet, based on glycemic indexes, constituted a intellectual scam and that it was dangerous for health ”.
As it is only fools who do not change their minds, we will pay tribute today to the good Dr. Fricker who now recommends to readers of his latest books who want to lose weight, not to eat potatoes or white bread given their high glycemic index.
For ten years, a large number of scientific studies have directly or indirectly demonstrated the interest of the glycemic index in the fight against obesity but also in the prevention of diabetes and cardiovascular illnesses.
A good hearer 🙂
