Simple and complex carbohydrates: let’s discover the differences together so we can organize meals in a healthy and balanced way. Carbohydrates are also called carbohydrates , sugars or saccharides, due to the sweet taste that distinguishes some of them, including the sugar par excellence, sucrose.
Carbohydrates are, after water, the most abundant components of the diet for almost all populations in the world . They should provide approximately 60% of an individual’s energy needs.
The main carbohydrates ingested with food are lactose, sucrose, cellulose and starch, and the latter provides more energy to our diet than any other substance.
Simple and complex carbohydrates
Carbohydrates are of two main types:
- simple carbohydrates
- complex carbohydrates
Simple carbohydrates include sugars found naturally in fruits, vegetables, milk and dairy products, but also sugars added during food storage and preparation. What is the difference? In general, foods with added sugars contain fewer nutrients than natural ones.
One way to avoid these sugars is to read the ingredient lists on food labels. Typically, the higher the ingredient in the list, the higher the added sugar content of the food.
Carbohydrates, let’s learn to read the labels
To avoid added sugars you can also:
- Choose water instead of sweetened carbonated drinks,
- Drink half a cup of 100% fruit juice instead of generic fruit juice,
- Eat some fresh fruit instead of dessert and avoid sweets with added sugar,
- Choose breakfast cereals without added sugars or with few added sugars. Starches and dietary fibers are the two categories of complex carbohydrates : starches, in fact, must be modified through digestion before the body is able to use them as a source of glucose. Starches and dietary fibers are found in a few foods, such as bread, breadsticks, pizza, cereals and some vegetables (potatoes, dried beans, peas); Dietary fiber is found primarily in vegetables, fruits, and whole grain foods.
Carbohydrates and blood sugar
When you eat, your blood sugar (glycaemia) level increases as a result of the intake of carbohydrates . This increase causes the beta cells of the pancreas to secrete insulin, whose task is to lower blood sugar. The response is faster the higher the glycemic load of the carbohydrates consumed.
Insulin
- facilitates the entry of glucose into muscle cells;
- it starts the storage of glycogen stores (i.e. carbohydrate stores ) in the liver and blocks the release of what is present;
- transforms surplus carbohydrates into fat;
- blocks the consumption of fats already present.
There is an insulin antagonist hormone, glucagon, which causes blood glucose levels to rise. If there is too much insulin or too little glucagon, hypoglycemia occurs with consequent brain suffering.
Glucagon
a) releases glycogen stored in the liver;
b) allows you to burn fat;
c) stimulates gluconeogenesis, favoring the conversion of amino acids into glucose by the liver.
The control of the system is based on the balance of the action of the two hormones. If you consume too many carbohydrates you have an excess of insulin which blocks the release of glycogen, the brain goes into crisis (this is the explanation for the drowsiness after a hyperglycidal meal or the sense of fatigue and listlessness that accompanies the days of many people who follow an incorrect diet) and requires energy that we try to reintroduce with other carbohydrates, making the situation worse.
An excess of carbohydrates makes you fat, does not burn fat, stimulates hunger more, makes you less physically active.
The distinction between simple and complex carbohydrates makes sense from a chemical point of view, but it is practically useless when it comes to explaining what happens to different types of carbohydrates within the body.
For example, the starch contained in white bread and French fries can clearly be classified as a complex carbohydrate, however the body converts it into glucose almost at the same speed with which pure glucose is assimilated. Fructose (fruit sugar) is a simple carbohydrate, but has a minimal effect on blood sugar.
Carbohydrates and glycemic index
However, there is a new parameter, the glycemic index, which aims to classify carbohydrates according to the speed and level with which they increase blood sugar levels in relation to the quantity of glucose consumed. Foods with a high glycemic index, such as white bread, cause blood sugar to rise rapidly, while those with a low glycemic index, such as whole oats, are digested more slowly and therefore cause blood sugar to rise more slowly and less abruptly.
A glycemic index of 70 or more is considered high, while a glycemic index of 55 or less is considered low.
Factors that influence the glycemic index
The glycemic index of foods depends on many different factors, including:
- Refining. Ground and refined cereals (i.e. without the bran and germ) have a higher glycemic index than whole grains.
- Type of starch. Starches have different chemical configurations. Some are easier to break down into glucose molecules. The starches contained in potatoes, for example, are digested and absorbed by the blood quite quickly.
- Fiber content. The sugars contained in fiber have a chemical structure that creates problems for the body when it comes to breaking them down. The richer a food is in fibre, the less digestible the carbohydrates it contains and the less glucose it can supply to the body.
- Maturation. Ripe fruits and vegetables tend to have more sugar than unripe ones, and therefore their glycemic index is generally higher.
- Fat and acid content. The more the food or meal is rich in fats and acids, the more the conversion of carbohydrates into glucose and the absorption of glucose into the blood slow down.
- Form. Finer ground grains are digested more quickly and therefore have a higher glycemic index than coarser ground grains.
Diets rich in high glycemic index foods, which cause rapid and dramatic increases in blood sugar, have been linked to an increased risk of
- diabetes
- cardiac pathologies
- overweight
Some preliminary research links these diets with
- macular degeneration in the elderly,
- ovulatory infertility,
- colorectal cancer
Foods with a low glycemic index, on the other hand, have proven useful for keeping type 2 diabetes under control and promoting weight loss.
Other research, however, indicates that the glycemic index has little effect on patients’ weight and health. This difference of opinion is normal in science and means that the importance of the glycemic index has yet to be precisely discovered. In the meantime, eating whole grains, legumes, fruit and vegetables, i.e. foods with a low glycemic index, is undoubtedly good for many aspects of health.
see also: The doctor named foods rich in calcium: Nuts, carrots and onions.
