Nutrition and our body

Due to food we take certain amounts of nutrients and energy. These compounds are necessary for the proper function of cells, organs, systems consequently the whole body’s. Human organism is resembled with a machine which is able to release the chemical energy which is contained in nutrients. According to the first Law of Thermodynamics, energy can neither be created nor destroyed, just converted from one form to another. Nutrients, from which the chemical energy is provided, are the carbohydrates, the proteins, the fats and the alcohol. These are called macronutrients. The energy provided by them elements is 4.2 kcal/g for carbohydrates, 4,3 kcal/g for proteins, 9,4 kcal/g for fats and 7 kcal/g for alcohol. Other compounds, called micronutrients, needed in smaller quantities are the vitamins (e.g. Vitamin C, Pyridoxine) and the minerals (e.g Zinc, Iodine) and control body’s functions. They contain no calories and their main role is to control functions such as absorption, digestion and metabolism of the nutrients and the creation of tissues or they may have a special role in the prevention and treatment of some diseases. Water makes up a nutrient category by itself. Most individuals need about 10 cups of water daily, from fluids and fruit. It is essential for the normal cell functioning. Ingestion, digestion, absorption, and metabolism are all processes the body uses to repair and maintain the body as a whole including any one of its many parts.

The daily amounts of macro- and micronutrients needed differ for each individual. Factors that play a key role are; age, sex, body size, pregnancy or lactation, physical activity and clinical state. In general the daily requirements change during life combined to the state that a person is being at that time. For example a teenage pregnant girl has significant differences in energy or vitamin requirements compared to an adult woman in the state of pregnancy.

An other case that an individual can have special requirements is in sports. An athlete’s nutritional needs differ a lot from the average man, even when the anthropometric sizes are the same or they are at the same age. The science of nutrition can define these increased needs in energy and micronutrients, offering this way proper amount, so that the body can meet its needs.

In addition, the body needs special combination of nutrients when there is infection or disease. Generally in every state that one or more of the organs do not function properly. Usually the appropriate diet can help to the problem’s elimination or even cure the abnormality. 

Consequently, optimum nutrition is a matter of getting enough of the proper quantities of macro and micro nutrients  a body needs to maintain proper health.

Maria Toumpi

Clinical Nutritionist - Dietitian MSc