[The Food and Nutrition Surveillance System (SISVAN) as a tool to monitor the nutritional status of children and adolescents in Brazil].

In Brazil, the Food and Nutrition Surveillance System (SISVAN) is the main tool in collecting and consolidating information on the nutritional status and the feeding habits of the population encompassed by primary health care services of the country. This study explores data from SISVAN to analyze the system's potential as a tool for monitoring the nutritional status of children and adolescents in the country. We seek to evaluate the evolution of the system's coverage rate in relation to the population regarding different age groups and geographic regions, how this coverage rate varies according to the characteristics of the Brazilian municipalities, and to what extent the results from SISVAN differ from representative sample surveys of the population. We present four main results. First, we documented that from 2008 to 2019, SISVAN significantly expanded its coverage; with a significant decrease, however, in 2020, reaching levels similar to those at the beginning of the series. Second, our results indicate that coverage is not homogeneous, being higher in the North and Northeast regions and among underage children. Third, there is a systematic association between the characteristics of the municipalities and the level of coverage of the system. Finally, SISVAN results differ from those presented by surveys representative of the general population. Jointly, the results of this study point to the need to refine the nutritional surveillance instruments on children and adolescents in Brazil.