Although the study design did not include an assessment of nutritional impact, it is to be expected that the increased nutrient intake may have a salutary health effect in the long term. Considering the high nutritional quality of the breakfast, the case of iron is of particular significance. The data confirm once again that school feeding programmes are an incentive for poor families to send their children to school. Of importance in this study is that this effect was observed over a period of 30 days. Because of its effects on attendance, it is possible to infer that the programme could be an incentive to keep children in school, a major problem in the educational system in Peru.
Error term includes the effect of school nested in study group.
Residual of weight after regressing it on height and age. Among them, the vocabulary test was the only one whose variability in the change of scores was great enough to be explained by the regression model. Moreover, the results of the regression showed that the treatment x weight-R interaction accounted for a significant portion of the variance of the vocabulary scores. Paradoxically, among children who received breakfast, the heavier children benefited the most. Moreover, among the controls, the heavier children performed less well than the rest of the group.