[Anemia and obesity: a paradox of the nutritional transition in Brazil].

The aim of this study was to analyze the growing prevalence of anemia and overweight/obesity as contrasting trends in Brazil's nutritional transition. Twenty-eight studies published on anemia in children and childbearing-age women were selected, based on statistical representativeness, standardization of laboratory methods, and World Health Organization criteria. Overweight/obesity in adults was assessed by body mass index: 25 to 29.9 kg/m(2) (overweight) and > or =30 kg/m(2) (obesity). Three surveys were compared for analysis of tendencies: 1974/1975 (36.4%), 1989 (53.5%), and 2002/2003 (51.9%) for overweight/obesity prevalence. In the most representative study on anemia among children (< 11 g/dL), the prevalence increased from 22.0% (1974) to 46.9% (1995/1996). For pregnant woman (< 11 g/dL), results ranged from 14.7 to 40.4%. Prevalence of anemia among children and overweight/obesity among adults showed similar tendencies over time. Recent evidence of reduction in anemia can be attributed to flour supplementation with iron and folic acid. Anemia and overweight/obesity are associated with significant changes in food intake as a substratum of the nutritional transition.