*2.4. Data Analysis*

Quantitative variables were presented as means (M) and standard deviations (SD), while frequencies and percentages (%) were used for qualitative variables. After verifying the normality of the variables by means of the Kolmogorov-Smirnoff test, a Student-T test for independent samples was used to perform a comparative analysis of the quantitative variables of body composition and physical fitness between the boys and the girls. In addition, to check for possible differences in the proportion of subjects that are in the different categories in the % of body fat for an adolescent population established by Moreno et al. (2006) [57], a Chi-square test was performed to check for the possible differences between genders. In order to analyse the degree of adherence to an MD (low, medium or high), both in the boys and the girls, in relation to the different variables of body composition and physical fitness, after checking homoskedasticity by means of Levene's test, a one-way ANOVA and, in the case of statistically significant differences, a Bonferroni post-hoc test, was performed. Furthermore, a Chi-square test was performed to check for the possible differences in each of the questions that compose the KIDMED questionnaire grounded on the normative levels of body fat % established by Moreno et al. (2006) [57]. The level of statistical significance was set as *p* < 0.05. All statistical analyses were carried out using the SPSS statistical package (version 18.0, SPSS Inc., Chicago, IL, USA).
