the anthropometric data of the Instituto de Orientación Profesional (Institute of Vocational Guidance) (IOP) is introduced and analysed. The IOP during its activity years (1917- 1935) advised youngsters of the city (mainly 13-19 y.) in their job seeking process.the statistical information provided by IOP has been analysed through two types of sources. One, secondary, based on statistics published in a monograph in the year 1936. Other, primary, from 305 individual cards found in the archives. Tables of growth of child and young populations of Spain as a model have been applied in order to assess the nutritional condition of the young attending the IOP.social and residential differences reflected in heights and weights of young applicants for employment (15-19 y.). 6.5 cm height and 4.5 kg weight as average between Wealthy and Middle and Working Class. Between 2 and 3 cm and 2 and 4 kg from residents in Ensanche compared to Casco Antiguo and Barriadas. Levels of moderate malnutrition would be of 17% and severe malnutrition between 3% and 5% in young population (13-16 y.) As determinant factor of height and weight, dilution hypothesis suggest the size of sibling. Regression results show a negative effect of this variable of 0.35 cm on height and 0.41 Kg on weight.anthropometrical and nutritional outputs from the IOP's young population revealed the consequences of social and spatial segregation and current Malthusian tensions in Barcelona in the first third of the 20th century.