Discussion
Sore
CURBING, SECONDARY
In this non-masked, cluster-randomised, controlled trial, a package of school-based nutrition education interventions delivered during one school semester (about 4 months) improved practices and knowledge related to dietary diversity and meal frequency among young adolescent girls. High reported exposure to the intervention components was achieved in the intervention group. We observed lower consumption of sweets in the previous 24 h, but no impact on consumption of any other junk foods.The diets of adolescent girls in our study had low diversity overall. Low dietary diversity among adolescent girls aged 10–19 years (broader than the 10–14 year age range in our study) was corroborated in a recent observational study in SNNPR, one of our study regions; the mean dietary diversity score was 3·6 food groups, and only 28% of participants consumed at least five food groups.Meal frequency knowledge was higher among adolescent girls and their parents in both study groups compared with knowledge that at least five food groups make up a diverse diet and that avoiding junk food and sugar-sweetened beverages is part of good nutrition. However, meal frequency was three meals per day on average in the control areas at endline; this was similar to findings from an observational study in Damot Sore district, SNNPR, in which 76% of 719 adolescent girls aged 10–19 years consumed three or fewer meals per day.Despite an intervention effect on the consumption of other sweets, more than half of the adolescent girls reported consuming junk food, with no differences in the consumption of fried and salty foods, baked sweets, or soda and sugar-sweetened beverages between study groups. Knowledge about avoiding junk food as part of good nutrition improved among adolescent girls and their parents between study groups, but knowledge did not translate into practice. This result might not be surprising, considering that consumption of unhealthy foods is influenced by a complex set of factors. Junk foods are designed to be tasty, convenient (ready-to-eat packaging), and easily available, and are subject to commercial advertisements. At endline, nearly all study schools had at least one food vendor within 1 min walking distance, mainly selling sweets and soda or sugar-sweetened beverages, and about a quarter of adolescent girls had seen or heard a food advertisement in the past 3 months. Therefore, nutrition education and telling adolescents not to eat junk foods that they crave or enjoy without changing their food environments might not be successful in curbing junk food consumption.Although it was not possible to disentangle the effects of individual components within our intervention package, exposure to at least two components was associated with improved outcomes. A previous study on the association between the combination of behaviour change interventions or number of contacts and child feeding practices showed that results are context specific;Parents had an essential role in the diets of young adolescents in our study. Although the adolescent girls spent time away from their parents throughout the school day, parents were still the primary source of and gatekeepers to their foods. Free school meals were not provided in any of our study schools, and only one intervention school had a canteen but no food items were observed, so adolescents were limited to foods from home, foods received from peers or others, or foods purchased from around the home or school premises. Nutrition education targeted to, and active involvement of, parents are crucial components of adolescent nutrition interventions. Evidence of improved food preparation by parents for their adolescent daughters and their home food environment were observed in the intervention group at endline.Our study addresses the important evidence gap on the effectiveness of nutrition education interventions to improve adolescents’ dietary practices, particularly in Ethiopia. Our randomised design lends confidence in attributing the observed impact and changes in outcomes to the interventions. Furthermore, the package of school-based interventions was relatively low cost to develop and implement. Total estimated programme costs (including programme staff salaries, materials and other resources, transportation, non-governmental organisation budget, and school staff salary) for programme reach per beneficiary was roughly US$43·22 per adolescent girl (grades 4–8) in the intervention schools, or, if considered school wide, $13·79 per student (boys and girls in grades 1–8).Study data collected were based on self-reports, which are subject to recall and social desirability bias. To minimise these biases, measures for the primary and secondary outcomes used locally available food examples or specific meal or snack times throughout the day with a short 24 h recall period. Adolescent girls were interviewed separately from their parents and the variation in intervention effects across outcomes also suggests that adolescents might not be reporting socially desirable responses. No hard clinical outcomes were included in this study because the endpoints were dietary behaviours. In relation to adherence among study participants, we assessed implementation fidelity by measuring exposure to programme inputs, delivery of interventions by school staff, and exposure to each intervention component among adolescent girls and their parents over the intervention period. Moreover, the primary analysis to assess effectiveness was prespecified as intention-to-treat analysis at endline; therefore, all participants remained in the study sample for analysis, regardless of adherence to the protocol. Our study was conducted during the COVID-19 pandemic, which affected school schedules and activities; however, there were no differences in the school conditions by study group. Selection bias is possible given that the schools were randomly allocated and unmasked before participants were enrolled in the endline survey, but we consider this bias to be minimal given that interventions were not rolled out to students and parents before the pandemic and took place after school enrolment at the start of the new academic year.In conclusion, a package of nutrition education interventions delivered in primary schools in Ethiopia was feasible to implement and effective in improving adolescent girls’ dietary practices. Reinforcing messages about eating diverse foods and eating more often resulted in incremental behaviour change related to dietary diversity and meal frequency; however, informing adolescents to avoid junk foods, without addressing their food environments, was not effective in reducing junk food consumption. Other intervention strategies might be required to change food environments, such as the provision or product placement of healthy food or snack options at or near schools, and behaviours particularly related to consumption of junk foods, which is a growing concern among adolescents even in the rural areas in Ethiopia, as in many other contexts.