The most important thing is that carbohydrates give energy to the most apparent functions in our body, such as moving or thinking. Learn more about the role of carbohydrates in our bodies.
Functions of carbohydrates
The most important thing is that carbohydrates give energy to the most apparent functions in our body, such as moving or thinking, and the “background functions” that we mostly overlook. During digestion, carbohydrates consisting of more than one sugar are broken down into their monosaccharides by digestive enzymes and absorbed directly, causing a glycemic response (see below). Glucose is an energy source in muscle, brain, and other cells.
Carbohydrates as an energy source and their storage
Carbohydrates broken down into main glucose are the preferred energy source for our body, like cells in our brain, muscles, and other tissues directly use monosaccharides for energy needs.
When not used directly, the body converts glucose into glycogen. When needed, for example, between meals, at night, during spores of physical activity, or during short periods of fasting, the body converts glycogen back into glucose to maintain a constant blood sugar level.
The brain and red blood cells are mainly dependent on glucose as an energy source, and they can use other forms of energy from fat in extreme circumstances, such as during very long periods of hunger. For that reason, we must keep our blood sugar constantly at an optimal level. Approximately 130 grams of glucose is needed per day to meet the energy needs of the adult brain alone.
The glycemic response and glycemic index
When we eat foods that contain carbohydrates, blood sugar levels rise and then fall, a process known as the glycemic response. It reflects the speed of digestion and absorption of glucose and the effect of insulin to normalize blood sugar levels. Several factors affect the rate and duration of the glycemic response:
The food itself:
- The sugars that make up the carbohydrate, e.g., fructose, have a lower glycemic response than glucose, and sucrose has a more inadequate glycemic response than maltose.
- The cooking and processing methods used.
- The number of other nutrients in the food, such as fat, protein, and fiber
The (metabolic) circumstances of each individual:
- The metabolism itself
- Time of day the food is consumed
- The effect of different foods (and the food processing technique) on the glycemic response is classified according to a standard, usually white bread or glucose, within two hours after eating. This measurement is called the glycemic index (GI).
- Foods with a high GI cause a more significant blood sugar response than foods with a low GI.