Nutrition and learning in Chilean school age children: Chile's Metropolitan Region Survey 1986-1987.

The objective of this study was to determine the interrelationship between the scholastic achievement (SA) test and nutritional status of a representative sample of 4,509 elementary and high school children from Chile's Metropolitan Region. Percentages of weight/age (W/A), height/age (H/A), and weight/height (W/H) were compared to WHO (World Health Organization) Tables, head circumference/age (HC/A) to the Tanner Tables, and brachial anthropometry to Frisancho's norms. Socioeconomic status (SES) was measured by means of Graffar's Modified Method; SA by means of a language and mathematics test. Statistical analysis included correlation, regression, and WHO risk-approach methodology. Results showed that HC/A was the anthropometric parameter with the greatest explanatory power in SA variance and was significantly greater in high school graduates who were 17 y old (r = 0.350; p < 0.001; r2 = 0.122) than in elementary school children, who were 6 y old (r = 0.227; p < 0.001; r2 = 0.049), with a relative risk of 2.1 and 1.5, respectively. The explanatory power of W/A and H/A in SA variance was significantly decreased, and no significant differences were observed among high school students. These findings confirm that HC/A is the most important anthropometric parameter associated with SA. Educational selectivity apparently relates to HC/A, and not to W/A or H/A. These results may be useful in planning nutritional and educational policies.