Carbohydrates – their significance, division into simple and complex... where is the most carbohydrate?

From a biochemical perspective, carbohydrates constitute a class of organic compounds whose molecular structure comprises carbon, hydrogen, and oxygen atoms, with the hydrogen-to-oxygen ratio frequently approximating the formula H₂O. They serve a pivotal role in metabolic processes as the primary energy substrate for cellular functions. Through enzymatic hydrolysis during digestion, they are broken down into simpler units—monosaccharides—among which glucose assumes a critical function as the universal "fuel" for tissues. Any surplus glucose not immediately required for energy expenditure undergoes conversion into storage forms: triglycerides (fats) within adipose tissue and glycogen in the liver and skeletal muscles. In accordance with contemporary dietary guidelines, the optimal energetic contribution of carbohydrates in daily nutrition should range between 40–55% of total caloric intake [1]. Particular caution is advised regarding foods characterized by a high glycemic index (GI > 70), including sugar-sweetened beverages, confectionery, and refined bread products, whose frequent consumption is associated with rapid fluctuations in blood glucose levels and an elevated risk of developing insulin resistance and atherosclerotic lesions. Preferred carbohydrate sources are those with a low to moderate GI (≤ 70), such as whole-grain cereals, legumes, and low-sugar fruits, which promote glycemic stability and support long-term metabolic well-being.

Carbohydrates are an important source of energy, 1 gram of carbohydrate provides about 4 kcal. In the form of glycogen, they act as energy storage in the human body, found mainly in the muscles and liver. An adequate supply of carbs in the diet prevents the burning of proteins, which have very important structural and regenerative functions.

The classification of simple sugars is based primarily on the number of carbon atoms in their structure. We distinguish those that contain, in their composition, from 2 to 7 carbon atomes: trioses, tetroses, pentoses, hexoses and heptoses. The commonly known glucose, fructose, mannoses and galactose monosugars belong to the hexose group and are monomers, which then form disaccharides, oligosaccharids and polysaccharide.

Carbohydrate compounds contain more than one simple sugar in their composition. We distinguish between oligosaccharides, which are composed of 210 simple sugars. This group includes disaccharids: maltose, which is made up of two glucose molecules, sucrose, made up from one glucose and one fructose molecule, and lactose, in which the composition is glucose, and galactose. The most commonly encountered are lactose intolerance, also known as milk sugar.

In a rational, well-balanced diet, the source of carbohydrates should be mainly whole grain cereals such as cashews, brown rice, and potatoes and root vegetables. Fruits and vegetables are also rich in carbs. Fruit in their composition consists mainly of simple sugars, so it is not advisable to consume them in large quantities, especially in fruit juices or processed foods. In addition to the naturally occurring carbs in plants, we are dealing with adding sugar to ready-made products.