Scientists have excavated the first megacities of the Trypillian culture, which arose on the territory of modern Ukraine and Moldova almost seven thousand years ago. About 15 thousand people lived in ancient cities with an area of ​​up to 320 hectares. These megacities were not only the largest settlements of their time, but are also considered the oldest cities in Europe. They were probably older than even the cities of Mesopotamia. Archaeologists have long tried to figure out how such large groups of people provided themselves with food with only Stone Age technology.

By analyzing carbon and nitrogen isotopes in hundreds of samples (mostly animal, human, and plant bones), scientists were able to figure out what role plants and animals played in human nutrition. The fact is that when food is consumed, the atoms in its composition are used by the human body to produce its own molecules. Based on what type of carbon or nitrogen atoms accumulate in human bones, the main food sources can be determined.

It turned out that a significant part of the cattle and sheep were kept on fenced pastures. Animal manure was used to intensively fertilize peas in particular. It and grains formed the basis of the human diet, which was not only high in calories, but also contained enough essential amino acids. And labor-intensive meat production, which requires the waste of food resources to feed animals, was practically not used. The complex system of pastures and fields lasted until the third millennium BC, when the cities of the Trypillian culture broke up into small settlements for social reasons.