Infant malnutrition and obesity in three population-based birth cohort studies in Southern Brazil: trends and differences.

The aim of this study was to compare the evolution of nutritional deficits and overweight in one-year-old children from three birth cohorts started in 1982, 1993 and 2004 in Pelotas, Southern Brazil. Samples from the 1982 and 1993 cohorts and all children from 2004 were weighed and measured, and their mothers interviewed. Anthropometric deficits and overweight were assessed using both NCHS and WHO growth standards. A comparison of the existence of nutritional deficits showed that, after a decline between 1982 and 1993, its prevalence stabilized between 1993 and 2004. Across the whole period, a decrease in all deficits was observed. Obesity, on the other hand, increased. A deficit in the ratio of body length to age was found to be strongly associated with family income. The group with income below one minimum wage was the only to present a significant reduction of stunting during the study period. The most significant improvements in the reduction of nutritional deficits occurred in the first half of the study period, while social differentials remained. Fighting malnutrition is still necessary among the 40% of the population considered poor, and must be accompanied by efforts to combat overweight which is being observed in all social strata.