Survey instrument

A modified version of the generic Global School Health Survey [18] questionnaire was adapted to suit the context of this study. The original questionnaire contained 84 items posted on unintentional and intentional injuries, tobacco use, alcohol and other drug use, high risk sexual behaviours, dietary behaviours and physical activity among adolescents, however, the current study made use of only the dietary behaviour questions. The questionnaire consisted of 12 items that solicited responses from the participants. Six items sought socio-demographic information and six items measured respondents’ dietary practices, including breakfast intake, fruit and vegetable consumption, frequency of carbonated drink consumption and frequency of sweets/toffees consumption. The internal consistency measure for the instrument yielded a reliability coefficient of Kuder-Richardson [KR20] formula 0.80. This value indicated high reliability and KR20 reliability was suitable for dichotomous variables.

Data collection procedure

Selected schools’ headmasters/mistresses were formally notified through the metropolitan, municipal/district education directors. Parental involvement could affect participants’ responses, hence, their consents waived, and informed consents obtained from the participants after the heads of the schools granted permission for the study. Data collection was done during closing periods of the schools in order not to disrupt contact hours. Participants were asked to answer the questionnaires after research assistants explained the importance of honesty on the part of subjects and enhanced confidentiality on the part the researcher. Participants completed the questionnaires in their classrooms and recorded their responses directly by ticking or writing their responses to the questions.

Data analysis

Data was coded and analyzed using the Statistical Package for Social Sciences ([SPSS] version 22.0 for Windows) after pre-screenings were initially piloted to ensure accuracy and appropriateness of the data. In order to make meaning out of the data, participants’ responses to how often they eat fruits and vegetables in a week were categorized into healthy and unhealthy dietary practices. Consumption of fruits and vegetable regularly or always was described as healthy dietary practices while unhealthy dietary practices, was when consumption of fruits and vegetables was sometimes or never. Frequency counts and percentages were employed to report on dietary practices among in-school adolescents in the region and Chi-square was used to determine socio-demographic disparities in the dietary practices. Further analysis was done using binary logistic regression to establish the relative influence of the socio-demographic factors on dietary practices among in-school adolescents in the region. The outcome variable was dietary practices (unhealthy vs. healthy) and predictor variables were age, sex, socioeconomic status, parental communication (classified as difficult to talk to parents or easy to discuss issues with parents), academic performance (self-reported academic performance), geographical location and religion.

Ethical approval

The study was approved by the Institutional Review Board, University of Cape Coast [UCCIRB/CES/2016/04] after scrutiny of the study protocol where parental consent was waived off. The permission of waiving parental consents was based on the premise that parental involvement may affect students’ responses, hence, parental involvement was waived with authority from WHO that when conducting a sensitive study among minors and parental involvement could result in social desirability that could affect responses from the minors, parental autonomy can be waived. Maintenance of confidentiality and anonymity of the participants was ensured throughout the study. Teachers were also excused from the classrooms and students asked to fold the answered questionnaires without their names and place it in a box provided in front of the classroom to ensure anonymity and confidentiality. Participation in the study was voluntary without any compulsion.

Sociodemographic variations of dietary practices

There was found to be a statistically significant difference among students in terms of gender, age, socioeconomic status, parental communication, academic performance, and geographical location as shown in Table 2. The results in Table 2 showed that 54% (n = 367) of girls engaged in healthy dietary practices compared to 46% of boys (n = 287) [χ² (df = 1) = 7.818, P = .005]. This outcome meant that girls were more likely to engage in the healthy dietary practice of eating fruits and vegetables than boys. In addition, 57% (n = 171) of in-school adolescents within the age group of 12–13 years were found to have engaged in healthy dietary practices, compared to those within the age group 14–15 years [χ² (df = 1) = 7.876, P = .005]. This outcome reveals that unhealthy dietary practices increase with age. This outcome calls for intensification of school regulation to ban the selling of junk food, toffees and carbonated drinks on school grounds and promote the selling of healthy food, such as fruits and vegetables. In addition, a statistically significant difference was found in terms of parental communication and healthy dietary practices [χ² (df = 1) = 5.812, P = .016]. It was observed that adolescents with easy parental communication 52% (n = 439) were more likely to consume fruits and vegetables than adolescents with difficult parental communication. Furthermore, students with above average academic performance 59% (n = 240) were found to have engaged in healthy dietary practices than students with average and below average academic performance [χ² (df = 2) = 30.682, P = .001]. The findings mean that in-school adolescents whose academic performances are above average know the importance of healthy dietary practices. Also, it means that knowledge about the essence of fruits and vegetables increase healthy dietary practices. Finally, differences were found in the geographical location [χ² (df = 2) = 26.750, P = .001] such that 59% (n = 278) of in-school adolescents from middle/central zones consumed fruits and vegetables more than adolescents from the coastal and northern zones. A possible reason could be the higher availability of fruits and vegetables in the middle/central parts of the region.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 2. Sociodemographic variations in the dietary practices.

https://doi.org/10.1371/journal.pone.0268319.t002

Nevertheless, there were no statistically significant differences between in-school adolescents in terms of their socioeconomic status and religious affiliation in relation to dietary practices. This result means that to engage in the healthy dietary practice of consuming fruits and vegetables is not dependent on the financial status of the parents or religious affiliation.

Socio-demographic factors predict healthy dietary practices among in-school adolescents

A binary logistic regression was conducted to find the strength of associations between socio-demographic factors and healthy dietary practices among in-school adolescents in the region. Odds ratios (OR) and confidence intervals (CI) were used to determine the strength of the association. The results in Table 3 showed that the whole model significantly predicted healthy dietary practices among in-school adolescents (-2LogL = 1747.5, χ² = 69.83, P = 0.001). Overall, socio-demographic characteristics of in-school adolescents explained 6.9% of the variance in healthy dietary practices in the region as Nagelkerke R² indicated a variance of 0.069.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 3. Binary logistic regression of socio-demographic predictors of healthy dietary practices among in-school adolescents.

https://doi.org/10.1371/journal.pone.0268319.t003

Results showed statistically significant variations in the odds of eating fruits and vegetables within gender, academic performance and geographical location. The result revealed that girls were 1.4 times more likely to eat fruits and vegetables than boys (OR = 1.36, 95% CI = 1.08–1.70, P = 0.007). This means that boys are at higher risk of unhealthy dietary practices than girls. Similarly, students with above average academic performance were 2.2 times more likely to engage in healthy dietary practices than those whose performances were average and below average (OR = 2.19, 95% CI = 1.56–3.08, P = 0.001). Also, students with average academic performance were 1.6 times more likely to eat fruits and vegetables than those with below average performance (OR = 1.59, 95% CI = 1.16–2.16, P = 0.004). In addition, students in the central part of the region were 1.8 times more likely to engage in healthy dietary practices than those from the southern part (OR = 1.79, 95% CI = 1.37–2.35, P = 0.001). Also, adolescents from the northern part of the region were not found to consume fruits and vegetables more than those from the southern part of the region (OR = 1.06, 95% CI = 0.97–1.56, P = 0.690). However, no statistically significant variations were found in the odds of eating fruits and vegetables within age (OR = 0.79, 95% CI = 0.60–1.03, P = 0.076), religious affiliation (OR = 1.10, 95% CI = 0.77–1.57, p = 0.592), parental communication (OR = 1.23, 95% CI = 0.98–1.56, P = 0.078) or socioeconomic status (OR = 1.12, 95% CI = 0.88–1.42, P = 0.358).

Socio-demographic variations in dietary intake

Health inequities is a major issue observed in the dietary practices among adolescents. This study observed disparities in terms of gender, age, socioeconomic status, parental communication, academic performance, and geographical location in relation to healthy dietary practices. These disparities are critical in terms proffering appropriate interventions to enhance healthy dietary practices and reduce prevalence of adolescent obesity. The finding that girls had healthier dietary practices than boys corroborates with Ranjit et al. [24] and Nilsen et al. [25] that the healthy dietary practice of fruit and vegetable intake is often higher among girls compared to boys. This observation prompts the need for increased physical activity in school among boys to increase better glucose metabolism and reduce the effect of unhealthy dietary practices on their body weight. Increased education on healthy dietary practices is also necessary.

The finding that the younger age group had healthier dietary practices than the older age group supports the findings of Ranjit et al. [24] and Pearson et al. [26] that younger adolescents engaged in healthier dietary practices than older ones. Harnack et al. [27] explained that soft drink and fast food consumption increased with age in adolescents in the United States. Similarly, Bere et al. [28] study in Norway posited that fast food consumption and the frequency of visiting fast food restaurants was higher among students in upper classes (ages 15–18) than students in lower classes (ages 12–14).

In terms of academic performance, the finding that students with above average academic performance had healthier dietary practices than those with average or below average performance is consistent with Falkner et al. [29] who found that unhealthy dietary behaviors are always found among students who have had to repeat their grade. The adolescents in the Central Region did not differ in terms of their socioeconomic status and dietary practices. This finding contrasts with the finding of Henningsen [30] that adolescents with low socio-economic position have a higher consumption of soft drinks and fast food than those with high socio-economic position. Also in contrast with this study, but similar to Fahlman et al. [31] also found that those with high socioeconomic position engaged in healthier dietary practices. Variations exist in adolescents dietary practices, adolescents from less affluent homes generally report unhealthy eating practices, however, affluence homes also influence consumption soda and soft drinks.

Predictors of dietary intake

Gender was a significant predictor of healthy dietary practices among in-school adolescents in the Central region with boys at more risk of engaging in unhealthy dietary practices. Unhealthy dietary practices may contribute to developing unhealthy weights and increasing the burden of obesity and CVDs among boys. This outcome corroborates with previous research findings [32]. These studies reported that girls were more likely to engage in the healthy dietary practice of eating fruits and vegetables than boys. The plausible explanation to these similarities could be that girls prefer to eat at home compared to boys. Although Layade and Adeoye [32] also found gender as a predictor of healthy dietary practices, they posited that males were more likely to consume fruits and vegetables than females. The possible reason for this difference in the finding could be because the current study sampled junior high school students while the previous study sampled tertiary students. The outcome also means that boys would lack essential nutrients from fruits and vegetables and suffer related consequences, resulting in the need to promote fruit and vegetable consumption among boys.

Furthermore, academic performance of in-school adolescents also predicted healthy dietary practices in the region, as adolescents with above average academic performance were more likely to eat fruits and vegetables than those with average or below average academic performance. This finding is consistent with previous research findings of Doku et al. [33] that academic performance of adolescents was a significant predictor of healthy dietary practices among adolescents, with students having above average academic performance being more likely to consume fruits and vegetables. The confirmatory reason for this outcome could be that students with high academic performance are aware of the importance of fruits and vegetables in their diet, and this could be responsible for high consumption of fruits and vegetables among this group [34]. Another plausible reason for the similarities in the findings could be that students with high academic performance eat fruits and vegetables because availability and purchasing ability of the students. Therefore, there is a need for education on the importance of fruits and vegetables among students with average and below average academic performance. Also, an effective intervention of implementing a healthy canteen intervention programme in the schools as recommended by Mohammadi et al [3] could be the surest of to improve students’ dietary intake.

Furthermore, this study also found that in-school adolescents in the southern part of the region were at higher risk of not eating fruits and vegetables than adolescents from the central part of the region. This could be as result of unavailability of fruits and vegetables in the southern part of Ghana and if available they are very expensive. This finding is in support of the previous research findings by Layade and Adeoye [32] and Othman et al. [35] on fruit and vegetable consumption by students in Nigeria, where they described geographical area and availability of fruits and vegetables in the community as a predictor of fruit and vegetable consumption among adolescents. This explains that availability and access to fruits and vegetables in a locality determine students’ consumption. Similarly, the study affirms the research report of Currie et al. [36] for HBSC, that the engagement in health behaviours patterned geographical differences, hence the explanation that certain health behaviours depicted certain patterns across geographical areas. This meant that health outcomes showed the pattern of life, culture, traditions and weather conditions of the geographical zones of people. Also, the outcome could be due to no or limited availability of fruits and vegetables on school campuses in the southern part of the region, contributing to inhibited intake, hence, there is a need to encourage the consumption of fruits and vegetables in schools. Nutritional needs during adolescence are increased due to the increased growth rate and changes in body composition associated with puberty [6]. However, poor dietary practices among school adolescents could contribute to obesity. Fruit and vegetable consumption should be promoted in our schools, especially among boys and adolescents living in the northern and southern parts of the region.