A large number of organic compounds are summarized under the term carbohydrates. These include sugars (these are the so-called “sweet” carbohydrates) and the “non-sweet” form, consisting of starch and fiber. Carbohydrates are our most important source of energy (4.1 kcal or 17 KJ per gram). The calorie content of both types of carbohydrate is approximately the same, but the “sweet” types are less healthy because they only provide “empty calories”, i.e. a lot of energy but hardly any vitamins and minerals.
What are sweet carbohydrates?
A distinction is made between simple sugars and double sugars.
Nutritionists call simple sugars monosaccharides. These include glucose = grape sugar, fructose = fruit sugar and galactose.
The double sugars, also known as disaccharides, include sucrose = beet sugar = cane sugar, lactose = milk sugar and maltose = malt sugar.
All of these sugars are also referred to by experts as easily absorbable carbohydrates because they are quickly absorbed by the body and enter the blood. They are found in sweet foods such as candy, chocolate, cakes, lemonade, canned fruit, dried fruit and honey. The latter contains 70% invert sugar. This is a mixture of fructose and glucose, ie easily absorbable (“less healthy”) carbohydrates.
The sugar substitutes that are part of the carbohydrates, called sugar alcohols by experts, also taste sweet, such as sorbitol, xylitol, mannitol, isomalt, lactitol and maltitol, etc. Their calorie content is slightly lower (2-4 kcal/g) and their sweetening power is only 60% in comparison to that of sucrose.
An increased intake of sugar substitutes can lead to osmotic diarrhea and flatulence. Products containing sugar substitutes are therefore labeled “Excessive consumption may have a laxative effect”.
What are non-sweet carbohydrates?
Non-sweet carbohydrates are also known as complex carbohydrates. They consist of many individual sugar molecules chemically linked together. They are broken down into their components during digestion. Since this is relatively lengthy, the feeling of fullness lasts longer than with simple carbohydrates such as sucrose and sweets.
Complex carbohydrates include starch and fiber.
Starch consists of multiple sugars, also known as polysaccharides or glycans. They are broken down into simple sugars during the digestion process because only then can the body absorb them. Grain products such as bread, pasta, rice and muesli are mainly starchy, but also legumes, potatoes and some types of vegetables.
Dietary fiber refers to the indigestible food components. Even if they are indigestible, they are by no means unnecessary. They have a digestive effect in the entire gastrointestinal area. Because a high-fiber diet requires thorough chewing and thus causes increased salivation, which is important for pre-digestion. Gastric emptying is delayed, resulting in a longer-lasting feeling of satiety. The volume and water content of the chyme are increased, peristalsis is increased and the intestinal passage time is shortened. This causes a regulated digestion. Overall, a high-fiber diet helps prevent diseases such as constipation, diverticulosis, diverticulitis, colon polyps, colon cancer , hemorrhoids, obesity, dyslipidemia and diabetes mellitus.
The body converts all carbon into glucose
The body can absorb simple sugars directly. Double and multiple sugars are broken down into simple sugars during digestion. Our body needs glucose to generate energy. Therefore, it converts simple sugars, such as fructose and galactose, into glucose in the liver. Depending on how quickly it can form glucose from the supplied carbon, the blood sugar level rises. Glucose goes straight into the blood. Fructose only increases it very slowly. Complex carbohydrates take the longest. The body counteracts this with insulin to ensure that the blood sugar level does not rise excessively when high consumption of easily digestible carbohydrates occurs.
If we eat more carbohydrates than is needed for the current energy supply, the resulting glucose is stored. To do this, the liver and muscles convert the glucose into glycogen, which is the storage carbohydrate of the human organism. However, the amount of glycogen that the body can store is only small (liver approx. 150 g). When the glycogen stores in the liver and muscles are replenished, the excess carbohydrates are converted to fat in the liver and stored in adipose tissue. Too much carbohydrate intake can lead to obesity.
With the help of the blood, the body transports the glucose to the cells. To generate energy, they break down glucose into carbon dioxide and water. This releases energy, namely 4.1 kcal or 17 kJ per 1 g of carbohydrates. If the blood glucose level falls between meals, the body makes up for it by breaking down the stored glycogen back into glucose and releasing it into the blood.
The glycemic index, or how quickly carbohydrates enter the blood
Depending on the type of carbohydrate contained, the same amounts of carbohydrate lead to a different increase in blood sugar. The glycemic index was developed in order to be able to compare carbohydrates with each other. Carbohydrates with a high glycemic index (sweets, bread, potatoes, etc.) are characterized by the fact that they are absorbed quickly, cause high glucose levels and lead to a correspondingly rapid and strong insulin response.
In contrast to sugar, sugar substitutes are absorbed more slowly and incompletely by the body. As a result, they have comparatively little influence on the rise in blood sugar levels. Its calorie content is 2-4 kcal per gram, but its sweetening power is only 60% compared to that of sucrose. Diabetics must count sugar substitutes against the prescribed amount of carbohydrates.
Complex carbohydrates are particularly healthy
At least half of the energy we get from food every day should come from carbohydrates. 2/3 of these should be polysaccharides, 1/3 can be mono and disaccharides.
Adults should also consume 30g of fiber. At least half of the fiber should come from whole grains, with the remainder coming from fresh fruits, vegetables, and other high-fiber foods. However, our eating habits are different.
We eat too sweet and at most 20g fiber per day
That means we eat too many easily digestible carbohydrates like sugar, buns, cakes and sweets. They contain hardly any vitamins and minerals, have a low satiety value and often make you hungry and thirsty. As a result, there is a risk that too large amounts of it will be eaten.
The usual result: obesity. In contrast, carbohydrates containing polysaccharides such as whole grains, potatoes and legumes are ideal for a complete diet. They are rich in vitamins, minerals and fiber and keep you full. Due to their low energy density and large volume, they are particularly suitable for people who constantly reduce their energy intake and have to control their appetite.
Also Read: 10 Main Principles Of Proper Nutrition