Glycemic index, glycemic load and Bivo
What follows is the translation of the original Italian article by Paola Salgarelli, biologist nutritionist, specialist in Food Science:
For a long time we have been speaking about how much it is important, concerning good nutrition, to prefer food with low glycemic index. Bivo, for example, it is food which not only allows us to have a balanced meal, but also one with low glycemic index (and we will explain in the present article the reason why that is true).
The Glycemic Index (GI) it is a parameter which indicates the ability and the speed of a food to increase glycemia (that is the concentration of glucose in the blood). In practice, when we eat a food rich in carbohydrates, the level of glucose in the blood progressively increases, following the digestion of starches and sugars contained in the food. The speed in which the food is digested and assimilated changes according to the kind of food we eat and is measured by the glycemic index.
The GI, therefore, categorizes food according to its influence on the sugar levels in the blood and regards only food with high content of carbohydrates, because food with high content of fats and proteins does not have an immediate effect on glycemia.
The types of food which we should prefer are those with low glycemic index because, lowering the speed in which sugars enter the blood, they help us to get under control the secretion of insulin, with many beneficial effects for our metabolism.
If glycemia increases, like it happens after a meal, the pancreas secretes insulin and order to the liver to take glucose from the blood and to stock it as fat, so that carbohydrates in excess are converted into fats and deposited in the fatty tissue.
This mechanism becomes problematic when, in response to the ingestion of food with high glycemic index, too much insulin is secreted. In this case glycemia lowers too quickly and the brain suffers a crisis, sending to the organism stimuli to intake more fuel (=hunger).
Instead, consuming food with low glycemic index, we monitor the production of insulin, with undoubted advantages like, for instance:
– prevent serious metabolic dysfunctions like type 2 diabetes;
– have a low-calorie diet without having sense of hunger;
– maintain our weight without too much effort;
– maintain our cholesterol low, since insulin is one of the factors which can stimulate its production.
Some charts exists for enlisting the majority of food, giving to each an evaluation from 1 to 100 according to its GI.
So, food can be classified as:
– Strong inducer of insulin (high glycemic index, greater than 80)
Ex.: potatoes, white bread, white rise, sucrose
– Moderate inducer of insulin (medium glycemic index, between 50 and 80)
Es.: bananas, cornflakes (non whole cornflakes), crackers and breadsticks (not whole breadsticks), basmati rice
– Slow inducer of insulin (low glycemic index basso, between 30 and 50);
Es.: pasta, not so sugary fruit (cherries, strawberries, pears, oranges)
– Food with minimal effects on insulin (very low glycemic index basso, lower than 30)
Es.: whole bread and whole bakery products, oats, cereal grains, food with low (or zero) content of carbohydrates (meat, fish, eggs, cheese)
In general, we can say that the kinds of food with low GI are mainly those rich in fibers, which slow down the gastric emptying, lowering the speed in which sugars enter the blood. Whole oats flour, ingredient of Bivo, is really high in fibers, so it has a low GI.
An important fact is that the protein and fats (included in borage oil and in flaxseed, two other ingredients of Bivo) lower the glycemic index as well.
The main ingredients of Bivo make it a kind of food with low GI, no doubt!
The GI is an important parameter, but for some kind of food it can be useful to calculate also the glycemic load.
In fact, the glycemic index has a limitation: it does not refer to the quantity of carbohydrates included in the specific food, but it is exclusively based on the speed in which the carbohydrates included in the food are digested.
The glycemic load of food, instead, considers also the quantity of carbohydrates included in the food. It can be obtained multiplying the GI for the quantity of carbohydrates included in the food and dividing it by 100.
Some intervals of values related to glycemic load has been studied. The categorization that follows is referred to an average portion of a single kind of food:
- High glycemic load: greater than 20
- Medium glycemic load: between 11 and 19
- Low glycemic load: lower a 10
The glycemic load is important mainly for the types of food containing low quantity of carbohydrates. These types of food can have a really hight glycemic index, but a low glycemic load. To understand this concept we give you a classic example, that of carrots which, if we consume them boiled, have a really high GI, equal to 90. Anyway, carrots have only 8 grams of carbohydrates for every one hundred grams.
So, the glycemic load of 100g of carrots is: (90 × 8) / 100 = 7,2
Therefore, if we just eat a low quantity of cooked carrots, our glycemic load is 7,2, considered to be low.
In conclusion, it is important to highlight that the glycemic index and glycemic load are fundamental tool in the evaluation fo the effects of carbohydrates which we intake in our diet. But let’s remember that there are many causes and mechanisms through which glycemia can be modified after a specific meal: some of those depends on a single kind of food, some other on the complete meal we ate, some others on the single person.
Paola Salgarelli, Biologist Nutritionist, specialist in Food Science