The paper shows how important it is to enter all the nutrients in appropriate proportions for the proper growth and development of the organism. Proteins are the basic building blocks of every, even the smallest part of the body. For a human use in the diet, proteins of animal or plant origin are most common. The main sources of protein of animal origin are meat and fish, milk and dairy products, and eggs. Vegetable proteins are found in legumes and cereals, beans, lentils, wheat, rice, corn, barley, oats, rye, and soy has a higher amount of protein. Today, insects are also becoming increasingly important alternative sources of protein. In addition to insects and plants, mushrooms are also an alternative source of protein. Mushrooms are rich in protein, and compared to most foods of plant origin, they have a well-balanced amino acid composition. People who consume only plant foods are called vegetarians, and the advantages or disadvantages of a vegetarian diet depend on the nutritional value of the food ingested.