[A study on breakfast and school performance in a group of adolescents].
OBJECTIVE
TO know the relationship between breakfast, from a qualitative perspective, and school performance.


METHODS
The study was performed in 141 students (70 males and 71 females) with ages ranging 12-13 years, of 1st grade of Mandatory Secondary Education (ESO) from an institute of Saragossa, by means of recalling the breakfast of the day before. Breakfast quality has been assessed according to criteria of the Kid study: GOOD QUALITY: contains at least one food from each one of dairy, cereals, or fruit groups. IMPROVABLE QUALITY: lacks one of the groups. INSUFFICIENT QUALITY: lacks two groups. POOR QUALITY: does not have breakfast. We considered that quality was improved only when a mid-morning snack with a different food from those taken with breakfast was added. Average mark at the end of the school year has been the criterion used to assess school performance. Statistical analysis of data gathered for the present study has been done with SPSS software. This analysis comprises descriptive and inferential statistics. For analysis of global significance between the differences the Analysis of Variance method has been applied, followed by post hoe tests with Bonferroni's and Turkey's methods to detect specific groups explaining global significance.


RESULTS
Average mark systematically increases as breakfast quality increases from an average score of 5.63 in the group with poor quality breakfast to 7.73 average score in the group with a good quality breakfast. An analysis of variance has been performed to study the statistical significance of the mean differences between both groups. The outcomes yield significant global differences between groups (p value = 0.001), i.e., the average mark significantly varies according to breakfast quality. When pooled quality of breakfast and mid-morning snack is analyzed, the average mark systematically increases as breakfast-snack quality increases, from an average mark of 5,77 in the group with poor or insufficient quality up to 7.61 in the group with good quality. An analysis of variance has been used to study the statistical significance between the mean differences between groups. The outcome was that there exist global significant differences between groups (p-value = 0.0004), i.e. the average mark significantly varies according to pooled breakfast-snack quality. Besides, we have analyzed the issue of the relative contribution of the snack quality to a determined breakfast quality. For that purpose, average marks for each combination of "breakfast quality" and "breakfast + snack quality". Thus, in the group of poor breakfast quality, those children remaining with poor or insufficient breakfast + snack quality have an average mark of 5.55, where-as those upgrading to "improvable quality" (just one child) have an average mark of 6.10. The students having an insufficient quality breakfast obtained an average mark of 5.91 if they remained with an insufficient or poor quality, and 6.30 if they upgraded to Improvable" quality, and 8.00 if they upgraded to good quality. Students having an "improvable" quality breakfast obtained an average mark of 6.82 if they remained at the same quality level, and 6.96 if they upgraded to good quality.


CONCLUSIONS
Relationship between breakfast quality and marks: 1. The average mark increases as breakfast quality increases (descriptive level). 2. The average mark significantly increases when breakfast quality is upgraded from poor or insufficient to good (inferential level). Relationship between pooled breakfast and mid-morning snack quality and marks: 3. The average mark increases as pooled breakfast and snack quality increases (descriptive level). 4. The average mark significantly increases when pooled breakfast and snack quality is upgraded from poor, insufficient, or improvable to good (inferential level). Specific contribution of mid-morning snack: 5. For a given breakfast quality, mean mark increases as pooled breakfast and snack quality increases (descriptive level).
Herrero Lozano
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R
Instituto Miguel Catalán, Departamento de Sanidad, Zaragoza, España. rherrero@comz.org
Fillat Ballesteros
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JC
D000124:Achievement; D000293:Adolescent; D002648:Child; D004032:Diet; D004493:Education; D005260:Female; D006801:Humans; D008297:Male