Abstract

Physical activity as a component of energy expenditure and physical activity as a determinant of child development are not congruent concepts. For the study of functional long-term effects of nutrition in infancy on later development, the age at which motor milestones are reached, conceptually, seems to be a more appropriate intermediary variable than physical activity per se. Data from a longitudinal study in Guatemala were used to test the hypothesis that early energy deficiency, as evidenced by growth retardation, is associated with delays in the reaching of motor milestones in the first 15 months of life and that these, in turn, are associated with measures of intellectual ability and educational achievements in childhood and adolescence. Birthweight did not predict anthropometric data or scores of motor and mental development tests at 15 months. Anthropometric data at 15 months, however, predicted mental and, even to a greater extent, motor test scores. Motor test scores and height, but not mental test scores, predicted results of cognitive tests during the preschool years. Motor test scores, but neither mental test scores nor anthropometric indicators, predicted cognitive performance in adolescence. These results suggest that one practical way of looking at possible long-term effects of chronic energy deficiency in infancy and early childhood may be by assessing its impact on milestones of motor development.