Height, weight and body mass index are the main indicators of human physical status. They are determined by the interaction of internal and external human growth factors. External factors could be divided (relatively) into socioeconomic (they are more important at early childhood), ethnic and cultural (play the important role at adolescence) and environmental (their impact is still not explored sufficiently). The most important socioeconomic factors are parental education, family income, number of children in family and occupation of parents. Very important external growth factors, such as child nutrition, level of physical activity and family living conditions depend on socioeconomic status of the fam-ly and the country as well. Hence, the socioeconomic factors are considered to have the biggest impact on children growth. The influence of ethnic and cultural factors is quite unclear: it is difficult to separate the influence of internal and external factors. Environmental factors include climate, geographic place, temperature, concentration of oxygen, pollution, noise level and others. However, the hierarchy and the interaction between internal and external (environmental) factors are not well understood during the different periods of child’s growth.
Life in Lithuania is now undergoing significant socioeconomic changes. We adopt Western way of life, our nutrition patterns change, the level of physical activity declines. Nevertheless, it is still unclear how negative external factors affect populations (us, for example) and what is the reason of the different growth patterns within the same population. That is why it is absofutely necessary to study children’s growth in completeness of many different external growth factors.