School - based nutritional education interventions

Schools are considered important channels of intervention because they offer access to large populations of adolescents and provide the opportunity to institutionalize programs in communities (Li et al., 2008). In addition, the closely supervised environment of a classroom, along with the potential for social support from fellow classmates and teachers, may enhance the effect of a school-based intervention over a home–based approach, which may be completed alone (Kothandan., 2014).

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Additionally, the school setting increases the likelihood of participants attending and using the materials of the intervention, due to the mandatory attendance requirements (Kothandan et al., 2014). Evidence by Kothandan et al. (2014) showed that a family-based intervention in the home - for obesity treatment by improving food intake (i.e. reduce energy intake) – demonstrated effectiveness for children under the age of twelve, whilst school based interventions were more effective for those aged between12-17.

Shirk et al. (2009) conducted a study in a high school for American adolescents (13-18 years old) over 3 weeks. Adolescents received nutrition education for 60 minutes, 4 days a week. The nutrition programme included education and activities such meal planning. For example, adolescents completed a 24-hour food recall at the beginning of the programme and were encouraged to modify it to make it healthier.

The author revealed that nutritional knowledge increased by 24% from pre- to post-intervention. Another study carried out in Palestine, showed a significant increase in nutritional knowledge by nearly 41% after 5 classroom-based lessons for adolescents (16-18 years old) (Farid et al., 2013). Furthermore, Abood et al., (2008) found a significant increase in nutritional knowledge amongst 551 adolescents (mean age 14.5 years) in the USA after a nutritional intervention of two 30-minute time slots over 1 week. All of these studies measured only nutritional knowledge as a main indicator of intervention success, and did not measure if the acquired nutritional knowledge had a positive impact on food intake.

However, other researchers have measured both nutritional knowledge and food intake. For example, Fahlman et al. (2008) conducted a pilot study to examine the effect of nutrition intervention (8 lessons within a month) on nutritional knowledge

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and behaviour change in 783 middle school students. Adolescents in the intervention group demonstrated a significant increase in nutritional knowledge by 53%, and also scored significantly higher than the control group post intervention. In addition, the study revealed that the intervention group significantly increased their fruit (3.25 portions/day) and vegetables intake (2.3 portions/day), as compared to the control group (fruit 2.41portion/day, vegetables 1.2 portions/day).

Another study, based in Khuzestan Province in Iran, examined the effects of a nutrition education programme on nutritional knowledge and dietary calcium in female adolescents enrolled in a junior high school (mean age 15 ± 0.7) (Naghashpour et al., 2014). In total, 188 adolescents were recruited - 95 into the intervention group and 93 into the control group. Adolescents in the intervention group received eight 30-minute to one-hour sessions during a two-month period, through lectures. The results showed a significant increase in nutritional knowledge of 17% at the 2-month follow-up, compared to baseline for the intervention group, as well as significant increases in dairy product consumption by 3 months.

Recently, Tavassoli et al. (2015) conducted a school-based health education intervention including 120 female adolescents in high schools in Isfahan city (Iran).

As before, the participants were divided randomly into two groups - intervention (60) and control (60) group – and the nutrition intervention was delivered through lectures over 6 sessions (45-60 minutes per session). The study showed a significant increase in nutritional knowledge post intervention of 88%, compared to pre intervention. The amount of increase in fruit intake was 149 grams/day (around 2 portions/day) and in vegetables 207 gram /day (around 2.5 portions/day).

Investigators in Libya carried out weekly nutrition education sessions for adolescents

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(n=189) in 6 schools for 3 months (Sachithananthan et al., 2012), revealing a significant reduction in chocolate, chips and fast food intake post intervention.

However, none of these nutrition education intervention looked at the range of factors that could influence adolescents’ food intake such as parents’ nutritional knowledge and their level of education, HFA and household income (Bjelland et al., 2011; Pearson et al., 2011; Campbell et al., 2013; Ansem et al., 2014; Shariff et al., 2015).

Nutricise 4 Life programme (N4L) is a school based nutrition education programme for adolescents (aged 16-18) in the USA (Blake et al., 2012). It is hypothesised that nutritional knowledge and dietary intake will improve over the 19-week duration of the intervention. The study revealed that nutritional knowledge increased significantly from pre- to post-intervention by 21%. However, no changes were observed in dietary intake. This may be that adolescents may have not recalled accurately what and how much they ate or it could be that cross contamination occurred as both intervention and control groups were at the same school. Also, it could be due to low HFA, household income, parents’ level of education or parents’ nutritional knowledge that influence adolescents’ food intake as stated earlier.

O’Nail et al. (2002) conducted a 4-year study with environmental support, offering more fruit and vegetables in the school cafeteria and stimulating parental involvement to increase the availability of fruit and vegetables in the home. The cohort comprised 14 to 15-year-old adolescents who were followed until the ages of 17-18 years. Nutritional knowledge and consumption of fruit and vegetables

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increased significantly post intervention in the intervention group compared to the control group

Although, nutrition education for adolescents is an important to improve their food intake, educating parents in particular mothers is an essential since they act as nutrition “gatekeepers” for their children, providing them with the ability and opportunity to make healthy food choices and make food available in the home which can influence adolescents’ food intake (Hanson., 2005; Hingle et al., 2010;

Campbell et al.,2013). Also, educating mothers is an essential as they can support and encourage their daughters to improve their food intake (e.g. eating more fruit and vegetables) (Shokrvash et al., 2013). For this reason some studies involved them in school based the intervention which could enhance its effectiveness.

2.4 Enhancing nutrition education interventions through parental