All the schools had been classified of the Chilean Ministry out of Training towards the three accounts, particularly lower-achieving schools, mid-finding schools and you will highest-gaining colleges, dependent new show of their children in all SIMCE examination ( thirty-two ) .
Anthropometric measurements and you may health standing
Standardized procedures were used to measure students’ weight to the nearest 0·1 kg, using a Seca scale (SECA, Hamburg, Germany), and height to the nearest 0·1 cm, using a Holtain stadiometer. All instruments were verified before measuring each participant ( Reference Gibson 33 ) . BMI (kg/m 2 ) and height-for-age were evaluated, and Z-scores were obtained according to the references of the Centers upforit for Disease Control, National Center for Health Statistics (USA) ( Reference Kuczmarski, Ogden and Guo 34 ) . Nutritional status was defined as follows: underweight, BMI Z-score
Socio-financial standing
Socio-financial updates (SES) is mentioned having fun with a level predicated on Graffar’s changed strategy and therefore was adjusted so you’re able to Chilean metropolitan and you may outlying communities ( Source Alvarez, Muzzo and you will Ivaple with the five socio-economic teams: 1=large (0·3 %); 2=mid–large (14·eight %); 3=center (38·step 3 %); 4=mid–lowest (45·6 %); and you will 5=reduced (step 1·1 %). Yet not, within investigation we blended these types of five categories toward three: high (1+2), middle (3) and you can lowest (4+5) SES.
Statistical research
Statistical analysis included performing ? 2 tests to compare categorical variables, and ANOVA and Bonferroni tests for comparison of continuous variables. After performing bivariate analyses with each potential confounding variable, including sex, grade, nutritional status, SES and school’s performance, we used logistic regression to assess the relationship between the nutritional quality of snacks at school (exposure) and individual academic performance in Mathematics and Language (outcome). In each case, the probability of passing the test was estimated using three models. In the second model, SES was added. Finally, a fully adjusted model contained all mentioned covariates with the addition of a variable denoting the school’s academic performance. Because the variable school’s performance was partly derived from the outcome variables, this adjustment may cause underestimation of the association, so we included models with and without adjustment for school’s performance. A P value of <0·05 denoted statistical significance. Data were processed using the statistical software package Stata SE for Windows version 12·0.
Overall performance
The sample is made upwards off thirteen·1 ( sd 2·3) year-dated men (52 %) and you will ladies (48 %) teenagers from lowest (44·3 %), middle (39·six %) and you may large (step 16·step one %) SES. It attended fifth (51·nine %) and you will 9th (48·step one %) grade publicly (34·8 %), partially backed (57·8 %) and private universities (7·cuatro %) regarding the Santiago Urban Area. In terms of nutritional updates, forty five % out of members was indeed fat otherwise fat. Nearly half the young (forty eight %) attended large-reaching universities, while 31 % and 23 % attended middle- and you will reasonable-reaching colleges, correspondingly.
In the sample, 56 % out of youngsters stated use of items from the treat date which were packed with body weight, glucose, salt and effort. Thirty-six % were thought about getting terrible-to-reasonable snacking, while merely 8 % was in fact thought to consume suit items in the snack date within college. Dining table step 1 comes with the detailed statistics of your take to. Average philosophy away from score inside the Language and you can Math was in fact significantly ong those with all the way down nutritional top-notch products at school (P=0·01). Brand new display regarding children consuming unhealthy delicacies in school try significantly highest certainly one of 9th graders (59 %; P=0·040), college students gonna lower-reaching universities (61 %; P=0·036), as well as certainly skinny and you will normal-weight professionals (69 % and you will 62 %, respectively; P=0·006).