Carbohydrates are a class of macronutrients that includes sugars. They are partially digested in the mouth, provided they are well chewed, before reaching the small intestine. They are composed of :
- all forms of sugars
- fruits and vegetables
How the body uses carbohydrates
In order to be usable by the body, carbohydrates are transformed into glucose during digestion. Glucose then passes into the bloodstream to reach the liver.
The liver takes some of this glucose for its own functioning. The rest is redistributed by the blood and used as a source of energy by the body’s cells.
Glucose overflow that has not been used by the liver or body cells is stored as glycogen in the liver and muscles for possible future use.
At the cellular level, glucose enters the cells through insulin produced by the pancreas. It then undergoes a series of transformations called the “Krebs cycle” in the mitochondria within each cell. At the end of the Krebs cycle, the transformed glucose can be used as energy.
The Krebs cycle is composed of two phases: the anaerobic phase and the aerobic phase. Let’s detail each of them.
- During the anaerobic phase, glucose, combined with vitamins, trace elements and enzymes, will be transformed into various elements: pyruvic acid, also known as pyruvate, lactic acid, oxaloacetic acid, citric acid, fumaric acid, malic acid, alpha-ketoglutaric acid, succinic acid. The elements thus produced are called “acidic and toxic intermediate metabolites”. The toxic intermediate metabolites will be disposed of as waste, and the acid intermediate metabolites move on to the second stage, which is the aerobic phase.
- In the aerobic phase, the acidic intermediate metabolites, always combined with the above-mentioned elements, are converted back into adenosine triphosphate, or ATP, by means of oxygen supply. The ATP thus produced can be used as a source of energy.
Rest assured, the Krebs cycle is not something you have to know by heart to practice as a naturopath. It is simply important to have some knowledge about how the body uses nutrients in order to choose the foods best suited to the physiological needs of the people who will come to you.
Carbohydrate intakes are important during prolonged exercise, and a reasonable dose of sugar allows the body to function properly so that each cell has enough energy to fulfil its role.
It’s time to talk about the glycemic index. Tackling this issue comes back to question the carbohydrate content of each food.
The glycemic index
The foods we eat do not all have the same sugar content. As a result, they do not all bring the same level of glucose into the blood, and therefore insulin.
The glycemic index, or GI, of foods can be broken down into 3 categories:
- High glycemic index, i.e. above 70, such as white sugar, confectionery, jams, bread, white rice, refined pasta, breakfast cereals, corn starch, fast food, potato chips, sodas and fruit juices.
- Medium GI (55-70) : whole or semi-complete rice or pasta, whole or semi-complete bread, legumes, whole fruits…
- Low GI (less than 55) : usually vegetables.
The higher the GI of the food, the higher the blood sugar level. The more a food undergoes industrial processing, the more its GI increases. The more vegetable protein and fibre a food contains, the lower its GI.
Here are some examples of medium and high glycemic indexes:
- white pasta: 55
- wholemeal pasta: 40
- potatoes: 90
- boiled potatoes : 70
- white bread : 95
- wholemeal bread : 50
Products with a high glycemic index ingested at the end of a meal require less insulin to be assimilated by the cells. Therefore, diabetics can consume them from time to time, but should not consume sugar at the beginning of the meal.
Fruits, on the other hand, produce more insulin than vegetables. Diabetics will therefore have to increase their consumption of vegetables and decrease their consumption of fruit.