All the colleges had been categorized because of the Chilean Ministry from Studies on three profile, specifically reasonable-finding colleges, mid-achieving schools and highest-reaching schools, dependent the newest results of the college students in all SIMCE screening ( thirty-two ) .
Anthropometric measurements and nutritional reputation
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 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-monetary standing
Socio-economic standing (SES) is actually mentioned playing with a size based on Graffar’s altered approach and that is adjusted to help you Chilean metropolitan and you will outlying communities ( Resource Alvarez, Muzzo and you will Ivaple into the five socio-monetary organizations: 1=higher (0·step three %); 2=mid–high (14·eight %); 3=middle (38·3 %); 4=mid–lower (45·6 %); and 5=low (1·step one %). Although not, in our studies we combined this type of five groups into about three: large (1+2), center (3) and you will low (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.
Performance
All of our test was developed up regarding 13·step 1 ( sd 2·3) year-old male (52 vanilla umbrella uživatelské jméno %) and you can female (48 %) teens away from reasonable (44·3 %), center (39·six %) and you will highest (step 16·step one %) SES. They attended fifth (51·9 %) and you may 9th (48·step 1 %) level in public places (34·8 %), partly backed (57·8 %) and private colleges (7·4 %) in the Santiago Urban Part. As for health standing, forty five % off players was basically heavy or overweight. Almost half the young (48 %) went to higher-achieving colleges, while 30 % and you can 23 % went to mid- and you may low-gaining colleges, respectively.
On the decide to try, 56 % off people advertised consumption of facts during the snack big date which were filled up with fat, glucose, salt and effort. Thirty-half a dozen percent were thought about to own worst-to-reasonable snack, whereas just 8 % was thought to eat healthy issues in the treat day at school. Desk step 1 provides the descriptive analytics of your attempt. Average thinking from results within the Code and Math was basically rather ong those with all the way down nutritional top-notch products at school (P=0·01). This new express from students taking unhealthy dinners in school is rather higher certainly 9th graders (59 %; P=0·040), students planning reasonable-gaining schools (61 %; P=0·036), together with certainly one of underweight and you can normal-pounds people (69 % and you will 62 %, respectively; P=0·006).
