The results related to the consistency and reliability of the questionnaire items, culturally adapted, and were obtained in a total of 55 questionnaires coming from the selected school. Thus, in the first measurement, the mean score obtained by the participants on the item referring to the weekly frequency of having breakfast with the parents was 1.36 (SD = 1.09), whereas in the second measurement, this mean value was 1.38 (SD = 1.46). Note that in the first measurement, 50.9% [95% CI = 37.1‒64.6] of the participants fell into the «0» score (they have breakfast with their mother or father every day of the week), whereas in the second measurement, this score was obtained by 40.0% [95% CI = 27.0‒54.1] of the children. The variances of the two measurements were 1.19 and 2.13, respectively, so the interclass correlation coefficient was 0.621 (p < 0.001), which reflects an acceptable concordance level for the sums of the scores28.
Regarding the item linked to the consumption of foods during school breaks, the mean score obtained in the first measurement was 1.32 (SD = 0.94), whereas in the second measurement, a mean score of 1.52 (SD = 1.34) was obtained. The percentage of children who stated they did not eat anything during school breaks any given day (score of “0” of the scale) was 38.2% [95% CI = 25.4‒52.3] in the first measurement, whereas in the second measurement this percentage was 29.1% [95% CI = 7.6‒42.9]. The variances of the two measurements were 0.89 and 1.81, respectively, so the interclass correlation coefficient was 0.627 (p < 0.001), which reflects a concordance level for the sums of the scores that can also be considered as acceptable28.
For the item linked to the weekly frequency of having breakfast, in the first measurement a mean score of 2.0 (SD = 1.26) was obtained, whereas in the second measurement, the mean value obtained was 1.87 (SD = 1.17). The score most frequently chosen, 3 “I have breakfast every day”, was selected by 56.3% [95% CI = 42.3‒69.7] in the first measurement, whereas in the second measurement that score was chosen by 41.8% [95% CI = 28.6‒55.9] of the participants. The variances of the two measurements were 1.59 and 1.37, respectively, thus obtaining an interclass correlation coefficient of 0.64 (p < 0.001).
After performing the reliability analysis, the questionnaire was passed on to the 12 school centers. A total of 470 children (9‒10 years old) participated in the study, as per the distribution of the participating centers (Table 1). The mean age was 9.8 years old (SD = 0.74), 54% were girls (n = 230; 95% CI = [49.2‒58.6]) and 46% were boys (n = 196; 95% CI = [41.3‒50.7]). The main sociodemographic results of the sample are summarized in Table 2.
| Center | N (Enrolled students) | N (Participating students in the sample) | % over the total sample | CI 95% |
| Escola Estadual de Ensino Médio “Dom Hermeto” | 140 | 125 | 27.41% | [23,5-31,6] |
| Instituto Estadual de Educação “Elisa Ferrari Valls” | 19 | 15 | 3.29% | [2,0-5,3] |
| Escola Estadual de Ensino Fundamental “Adir Mascia” | 73 | 64 | 14.04% | [11,1-17,5] |
| Escola Estadual de Ensino Fundamental “Antonio Mary Ulrich” | 32 | 24 | 5.26% | [3,5-7,7] |
| Escola Estadual de Ensino Fundamental “Iris Valls” | 34 | 30 | 6.58% | [4,6-9,2] |
| Escola Estadual de Ensino Fundamental “Paso de Los Libres” | 26 | 23 | 5.04% | [3,3-7,4] |
| Instituto Estadual “Romaguera Correa” | 20 | 17 | 3.73% | [2,3-5,9] |
| Escola Estadual de Ensino Fundamental “Hermeto Jose Pinto Bermudez” | 51 | 37 | 8.11% | [5,9-10,9] |
| Escola Estadual de Ensino Médio “Senador Salgado Filho” | 26 | 23 | 5.04% | [3,3-7,4] |
| Escola Estadual de Ensino Médio “Professora Lilia Guimaraes” | 54 | 42 | 9.21% | [6,8-12,2] |
| Colégio Estadual “Dr Roberval Beheregaray Azevedo” | 46 | 32 | 7.02% | [5,0-9,7] |
| Escola Estadual de Ensino Médio “Embaixador Joao Baptista Lusardo” | 37 | 24 | 5.26% | [3,5-7,7] |
| Total | 558 | 456 | 100.00% | |
Table 1: Sample distribution by participating centers. 12 schools of Uruguaiana city were included in the sample.
| Variables | n | Media | Standard Deviation | |
| Age (years) | 423 | 9.8 | 0.74 | |
| Number of brothers or sisters | 318 | 2.07 | 1.48 | |
| | | | |
| Qualitative variables | Categories | n | % | CI 95% |
| Sex | Women | 230 | 54 | [49,2-58,6] |
| Mens | 196 | 46 | [41,3-50,7] |
| Class | Morning class (09:00a.m.-14:00p.m.) | 173 | 38 | [33,7-42,5] |
| Afternoon class (15:00-20:00p.m) | 258 | 56.7 | [52,1-61,2] |
| Morning-afternoon class (10:00-13:00/ 15:00-17:00p.m) | 24 | 5.3 | [3,6-7,7] |
| Nationality | Brasil | 468 | 99.6 | [98,4-99,8] |
| Others (Argentina, Uruguay) | 2 | 0.4 | [0,04-1,2] |
| Family living situation | Alone with the mother | 77 | 17.6 | [14,3-21,5] |
| Alone with the father | 19 | 4.3 | [2,8-6,7] |
| With the mother and her new partner | 20 | 4.6 | [2,9-6,9] |
| With the father and his new partner | 9 | 2.1 | [1,0-3,8] |
| With father and mother | 280 | 64.2 | [59,6-68,5] |
| With other adults | 31 | 7.1 | [5,0-9,9] |
| Does your father work? | Yes, he works | 375 | 83.5 | [79,8-86,6] |
| He doesn't work | 30 | 6.7 | [4,7-9,4] |
| I don't know | 22 | 4.9 | [3,2-7,3] |
| I haven't contact with my father | 22 | 4.9 | [3,2-7,3] |
| Type of father's occupation | 0 Armed forces, police, fire and military | 1 | 0.2 | [-0,21-0,6] |
| 1 Senior members of the government, managers of public interest organizations and companies and managers | 1 | 0.2 | [-0,21-0,6] |
| 2 Science and arts professionals | 8 | 1.8 | [1,5-2,3] |
| 3 Level technicians | 11 | 2.4 | [1-3,8] |
| 4 Administrative service workers | 25 | 5.6 | [3,4-7,6] |
| 5 Service workers, retail salespeople in stores and markets | 199 | 44.2 | [39,6-48,8] |
| 6 Agricultural, forestry, hunting and fishing workers | 0 | 0 | [0,0-0,0] |
| 7 Industrial and service production workers | 6 | 1.3 | [0,3-2,4] |
| 8 Maintenance and repair workers | 3 | 0.7 | [-0,1-1,4] |
| Does your mother work? | Yes, she works | 288 | 63.7 | [57,9-66,9] |
| She doesn't work | 144 | 31.8 | [27,7-36,3] |
| I don't know | 14 | 3.1 | [1,5-4,7] |
| I haven't contact with my mother | 6 | 1.3 | [0,3-2,4] |
| Type of mother’s occupation | 0 Armed forces, Police, fire and military | 10 | 2.2 | [0,8-3,6] |
| 1 Senior members of the government, managers of public interest organizations and companies and managers | 3 | 0.7 | [0,1-1,4] |
| 2 Science and arts professionals | 5 | 1.1 | [0,1-2,1] |
| 3 Level technicians | 12 | 2.7 | [1,2-4,1] |
| 4 Administrative service workers | 25 | 5.6 | [3,4-7,7] |
| 5 Service workers, retail salespeople in stores and markets | 175 | 38.9 | [34,4-43,4] |
| 6 Agricultural, forestry, hunting and fishing workers | 18 | 4 | [2,2-5,8] |
| 7 Industrial and service production workers | 41 | 9.1 | [6,4-11,8] |
| 8 Maintenance and repair workers | 49 | 10.9 | [8,0-13,8] |
Table 2: Sociodemographic and characteristics of the sample. Mean and deviation of quantitative variables and frequencies and confidence interval of qualitative variables.
Variables linked to breakfast are summarized in Table 3. 24% (95% CI = [18.8‒28.2]) had not eaten breakfast the day they completed the questionnaire. 49.3% (95% CI = [44.7‒54.0]) had breakfast every day with either parent, 6.4% (95% CI = [4.2‒8.7]) with both their parents 4 to 6 days a week, 14.7% (95% CI = [11.4‒17.9]) 1 to 3 days a week, 11.1% (95% CI = [8.2‒14.0]) less than one time a week, and 14.2% (95% CI = [10.9‒17.5]) never had breakfast with their parents. With respect to the frequency of weekly breakfast, 18% (95% CI = [14.4‒21.6]) of the school children had breakfast every day, another 18% (95% CI = [14.4‒21.6]) 5 to 6 days a week, 6.9% (95% CI = [4.5‒9.2]) 1 to 4 days a week, and 51.8% (95% CI = [47.1‒56.4]) stated they did not have breakfast any given day of the week.
| Variables | Categories | n | % | CI 95% |
| Have you had breakfast today in the morning (before 11am)? | Yes | 342 | 76 | [72,5-79,5] |
| No | 108 | 24 | [18,8-28,2] |
| Breakfast classification | Sweets, pastries and salty snacks | 14 | 3.1 | [1,50-4,7] |
| Red, processed and could meats | 31 | 6.9 | [4,5-9,3] |
| Milk, lean meats, legumes, nuts, eggs | 157 | 34.9 | [30,5-39,3] |
| Vegetables and fruits | 110 | 24.4 | [20,5-28,4] |
| Bread, pasta, rice, potatoes | 47 | 10.4 | [7,6-13,3] |
| How often do you have breakfast with your mother and/or your father? | Everyday | 222 | 49.3 | [44,7-54,0] |
| 4-6 days per week | 29 | 6.4 | [4,2-8,7] |
| 1-3 days peer week | 66 | 14.7 | [11,4-17,9] |
| Less than once a week | 50 | 11.1 | [8,2-14,0] |
| Never | 64 | 14.2 | [10,9-17,5] |
| How many days a week do you have breakfast? | Everyday | 81 | 18 | [14,4-21,6] |
| 5-6 days per week | 81 | 18 | [14,4-21,6] |
| 1-4 days per week | 31 | 6.9 | [4,5-9,2] |
| None | 233 | 51.8 | [47,1-56,4] |
Table 3: Breakfast habits within the sample. Frequencies and confidence interval of breakfast habits variables.
The results related to the hypothesis contrast are presented in Table 4. No statistically significant difference was observed between having had breakfast and gender, nor with the co-living situation (p > 0.001). No correlations were observed with whether or not the father or mother worked, or with the type of work they did according to the Brazilian classification of occupations (p > 0.001). However, a significant relationship was found between the frequency of having breakfast with their father or mother and having had breakfast on the day of testing (p < 0.001).
| Frequency Breakfast today (Yes or No) | Statistical Value Pearson's chi-squared | Level of significance |
| N(%) | | |
| Sex | Males | 1.961 | p = 0.161 |
| 165 (73.7%) | | |
| 155 (79.5%) | | |
| Women | | |
| 59 (26.3%) | | |
| 40 (20.5%) | | |
| Family living situation | Alone with the mother | 0.929 | p = 0.968 |
| 60 (77.9%) | | |
| 17 (22.1%) | | |
| Alone with the father | | |
| 13 (68.4%) | | |
| 6 (31.6%) | | |
| With the mother and her new partner | | |
| 16 (80.0%) | | |
| 4 (20.0%) | | |
| With the father and his new partner | | |
| 7 (77.8%) | | |
| 2 (22.2%) | | |
| With father and mother | | |
| 210 (76.4%) | | |
| 65 (23.6%) | | |
| With other adults | | |
| 22 (75.9%) | | |
| 7 (24.1%) | | |
| Does your father work? | Yes. he works | 5.519 | p = 0.138 |
| 277 (82.4%) | | |
| 91 (85.8%) | | |
| He doesn't work | | |
| 25 (7.4%) | | |
| 5 (4.7%) | | |
| I don't know | | |
| 14 (4.2%) | | |
| 8 (7.5%) | | |
| I haven't contact with my father | | |
| 20 (6.0%) | | |
| 2 (1.9%) | | |
| Type of father's occupation | Armed forces. police. fire and military | 5.618 | p = 0.690 |
| 0 (0.0%) | | |
| 1 (1.7%) | | |
| Senior members of the government. managers | | |
| 1 (0.5%) | | |
| 0 (0.0%) | | |
| Science and arts | | |
| 7 (3.6%) | | |
| 1 (1.7%) | | |
| Level technicians | | |
| 9 (4.6%) | | |
| 2 (3.4%) | | |
| Administrative | | |
| 19 (9.7%) | | |
| 6 (10.2%) | | |
| Service. retail salespeople | | |
| 151 (77.4%) | | |
| 48 (81.4%) | | |
| Agricultural. forestry. fishing | | |
| 1 (0.5%) | | |
| 0 (0.0%) | | |
| Industrial and production | | |
| 4 (2.1%) | | |
| 1 (1.7%) | | |
| Maintenance and repair | | |
| 3 (1.5%) | | |
| 0 (0.0%) | | |
| Does your mother work? | Yes. she works | 3.042 | p = 0.385 |
| 216 (63.7%) | | |
| 65 (61.3%) | | |
| She doesn't work | | |
| 110 (32.4%) | | |
| 34 (32.1%) | | |
| I don't know | | |
| 8 (2.4%) | | |
| 6 (5.7%) | | |
| I haven't contact with my mother | | |
| 5 (1.5%) | | |
| 1 (0.9%) | | |
| Type of mother's occupation | Armed forces. police. fire and military | 10.108 | p = 0.342 |
| 10 (3.9%) | | |
| 0 (0.0%) | | |
| Senior members of the government. managers | | |
| 2 (0.8%) | | |
| 1 (1.3%) | | |
| Science and arts | | |
| 3 (1.2%) | | |
| 2 (2.5%) | | |
| Level technicians | | |
| 10 (3.9%) | | |
| 2 (2.5%) | | |
| Administrative | | |
| 19 (7.4%) | | |
| 6 (7.5%) | | |
| Service. retail salespeople | | |
| 129 (50.0%) | | |
| 46 (57.5%) | | |
| Agricultural. forestry. fishing | | |
| 16 (6.2%) | | |
| 2 (2.5%) | | |
| Industrial and production | | |
| 30 (11.6%) | | |
| 11 (13.8%) | | |
| Maintenance and repair | | |
| 39 (15.1%) | | |
| 10 (12.5%) | | |
| Breakfast frequency with parents | Everyday | 70.263 | p = 0.000* |
| 203 (61.9%) | | |
| 19 (18.4%) | | |
| 4-6 days a week | | |
| 22 (6.7%) | | |
| 7 (6.8%) | | |
| 1-3 days a week | | |
| 43 (13.1%) | | |
| 23 (22.3%) | | |
| Less than once a week | | |
| 30 (9.1%) | | |
| 20 (19.4%) | | |
| Never | | |
| 30 (9.1%) | | |
| 34 (33.0%) | | |
Table 4: Contingency table. Analysis of the association between breakfast frequency and different breakfast habits variables. The accepted statistical significance level for the hypothesis contrast is set at p < 0.05

Figure 1: Sampling. A random sampling is performed by clusters of the 24 urban public schools of the city and 12 schools were included. Please click here to view a larger version of this figure.

Figure 2: Kappa index calculation. To evaluate the reliability and reproducibility of the transcultural adaptation of the questionnaire, the Kappa indexes of concordance of the items are calculated. Please click here to view a larger version of this figure.

Figure 3: Descriptive analysis. Frequency distributions of qualitative variables and central tendency and dispersion of quantitative variables. Please click here to view a larger version of this figure.

Figure 4: Chi-square test. Determine the association or independence of two qualitative variables. Please click here to view a larger version of this figure.

Figure 5: Student’s t-test. The determination of the differences between two sample variations and for the construction of the confidence interval. Please click here to view a larger version of this figure.