10 BIODIVERSITY, OCCURENCE OF ORGANISMS AND THEIR EXTINCTION IS THE RESULT OF EVOLUTION

Food as a rocket fuel of living organisms

Animals including humans are eukaryotic heterotrophic organisms whose source of energy and building materials are organic compounds that have been produced by photoautotrophic organisms (mainly plants, but also cyanobacteria or algae). The primary source of energy on Earth is the Sun, and heterotrophic organisms obtain it through autotrophic organisms.

Getting energy through digestion

Thus, heterotrophic organisms obtain energy and building substances by digestion of food. They feed on biomass which was produced by photoautotrophic organisms (cyanobacteria, algae, plants) as producers. Heterotrophic organisms from this point of view are called consumers because they consume what the producers have created. Consumers are then divided into herbivores, carnivores and omnivores. Herbivores feed exclusively on plants, carnivores on meat and omnivores feed on both.

Human being

Humans can be classified as omnivores; it is natural for them to consume plant and animal foods and various products made from them. In this context, the issue of vegetarianism or veganism as alternative nutritional dietary styles is often debated. It is generally accepted that animal products contain some substances (amino acids or vitamins) which cannot be completely substituted by the herbal form. Therefore, it is inappropriate and risky in terms of health to lead children from an early age to vegetarianism because there may be disturbances in growth and development in general.

Eating disorders

In the context of nutrition in children, eating disorders such as obesity, anorexia nervosa, bulimia nervosa and others are often discussed. One of the causes is the inappropriate treatment of food in families, when it is attributed too large or, conversely, insufficient significance. Both extremes can subsequently lead to the child not eating enough of varied foods, eating little or overeating. The current problem is also catering in school canteens and buffets. Here we can also include the issue of healthy snacks that children bring from home or buy at school.

In general, the diet of children should be as varied as possible. It should contain all groups of nutrients – carbohydrates, proteins and fats. Wholemeal bread, vegetables and fruits are recommended as a source of carbohydrates. The source of proteins can be cheese, yoghurt or high-quality ham or legumes. The source of fats can be vegetables and animal fats. Children usually do not have a problem with cholesterol, so it is not a problem to spread butter on the bread for their snacks instead of less digestible hydrogenated vegetable fats. The source of vitamins and minerals is fruit and vegetables.