Is obesity replacing or adding to undernutrition? Evidence from different social classes in Brazil.

OBJECTIVE: To describe time trends in under- and overnutrition in different regional and income strata of the child and adult population of Brazil.
DESIGN: Nation-wide surveys conducted in 1975, 1989 and 1996/7 in probabilistic samples of 1-4-year-old children and adults 20 years and over. Time trends refer to stunting, wasting and overweight prevalences among children and age-adjusted underweight and obesity prevalences among adults (95% confidence intervals included).
SUBJECTS: Individuals examined by each survey in each age group ranged from 1796 young children in 1996 to 78031 adults in 1975.
SETTING: North-eastern and south-eastern regions of Brazil.
RESULTS: Undernutrition indicators declined intensively and continuously among children and adults in all region and income strata. Obesity remained low and relatively stable among children, but increased intensively and continuously in all regions and income strata among adult males. Obesity also increased intensively and continuously among adult women from the less economically developed region of Brazil (the north-eastern region) and among lower-income women from the more developed region (the south-eastern region). Higher-income women from the more developed region had a significant increase in obesity from 1975 to 1989, followed by a significant decline from 1989 to 1997.
CONCLUSIONS: Undernutrition in young children is being controlled in Brazil without evidence of increasing obesity. However, obesity is rapidly replacing undernutrition in most gender, region and income strata of the adult population. Adult obesity is already more frequent than adult undernutrition in the more economically developed region, among all higher-income groups, and also among lower-income women living in the more developed region. These lower-income women are significantly more exposed than their higher-income counterparts to both undernutrition and obesity.