[Breast feeding and the nutritional status of Chilean children].
The purpose of this work was to describe the diet of children under 18 months of age and its relationship to nutritional status. For this purpose, in 1993 a prevalence study was carried out on children who received care from the National Health Services System of Chile. The Chilean public health system provides care to 75% of children under 6 years of age and especially to children of families in the lower strata of income distribution in the country. Participants in the study were 9330 children under 18 months old who were randomly selected from 102 of the 320 urban clinics throughout the country. The type of food these infants had received the day prior to the interview (breast milk exclusively, breast milk plus solid food, formula exclusively, formula plus solid food) and their nutritional status relative to the standards of the National Center for Health Statistics (United States of America) and of WHO were determined. Children with z values for weight-for-age between -1.0 and -2.0 standard deviations were considered at risk for malnutrition, and those with z values under 2 standard deviations were classified as malnourished. The prevalences of exclusive breast-feeding at the first, third, and sixth months of life were 86.5%, 66.7%, and 25.3%, respectively. Some 12.1% of the participants showed low weight for age; 30.7%, low height for age; and 35.7%, overweight. The magnitude of weight-for-age deficiency was 1.2 to 5 times greater among children who were fed milk substitutes than among those who received breast milk. Breast-feeding also had a positive effect on height. These results confirm the benefits of exclusive breast-feeding until 6 months of age, the need to supplement the child's diet with solid food after that age, and the breast-feeding's protective effect on the nutritional status of children of all the ages studied.