Hunger - a natural feeling which forces live beings searching for livelihood. And recently researchers have found out how hunger influences one’s emotional condition. It appears, easy feeling of hunger can make a person happier.

When an organism receives not enough calories, it starts producing a hormone ghrelin. This hormone signals a brain that it is necessary to eat. Scientists assumed that this hormone has a by-effect - it operates as an energizer.

American scientists changed ghrelin’s level in a mice’s organism in various ways. Mice with lowered ghrelin’s level seemed more oppressed and passive. But their condition could be changed by means of an energizer. And mice with raised ghrelin’s level, on the contrary, were very active and sociable and investigated new territory willingly.

In such tests behaviour and reactions of mice are always very similar to human. Therefore scientists are assured that results of researches can be referred also to people to the full.