Effect of a school-based education intervention on diet quality among adolescent girls

The proposed intervention is a school-based nutrition education program targeting diet quality among rural adolescent girls in southwest coastal Bangladesh. The intervention will span 12 weeks, with one 60-minute session per week delivered during school hours by trained facilitators. Each session will begin with a brief 10-minute introduction to engage participants, followed by 50 minutes of structured content delivery focusing on nutrition knowledge, perceived risks of poor diet, perceived benefits of healthy eating, addressing barriers, and enhancing self-efficacy and cues to action, guided by the Health Belief Model (HBM). The sessions will use interactive and participatory teaching approaches, including group discussions, question–answer activities, storytelling, and the use of visual aids such as flip charts and posters. Students will also receive printed workbooks and activity sheets to complete during and between sessions, containing exercises such as identifying food groups, drawing balanced plates, and recording their daily meals. The printed workbooks and activity sheets have been specifically designed for this study using content adapted from the Bangladesh National Dietary Guidelines (Bangladesh Institute of Research and Training on Applied Nutrition, 2020) and the Food Pyramid for Bangladesh (Institute of Nutrition and Food Science, University of Dhaka). The knowledge component covers dietary diversity, food groups and their functions, nutrient sources, the Bangladesh dietary guidelines, and the food pyramid. The perceived susceptibility and severity component addresses the consequences of unhealthy eating, malnutrition, and micronutrient deficiencies. The perceived benefits component highlights the advantages of healthy dietary behaviours for growth, school performance, and future safe motherhood. The perceived barriers component focuses on affordability issues, misconceptions about nutritious foods, food taboos, and menstruation-related myths, with strategies for overcoming them through affordable, locally available options. The self-efficacy and cues to action component includes practical demonstrations, healthy tiffin promotion, interactive cooking examples, distribution of simple nutrition guides, encouragement of school and home gardening, teacher engagement, peer-led adolescent clubs, and advocacy for school canteens with healthy food options. Teacher engagement will include activities such as teachers attending selected sessions, integrating nutrition topics into regular lessons, supervising school gardening and adolescent clubs, and helping monitor students’ tiffin boxes to encourage healthy eating practices. All educational materials, including teacher handouts and printed nutrition guides, have been specifically designed for this study using content adapted from the Bangladesh National Dietary Guidelines (Bangladesh Institute of Research and Training on Applied Nutrition, 2020) and the Food Pyramid for Bangladesh (Institute of Nutrition and Food Science, University of Dhaka). Most of the sessions will be conducted by a PhD student (the student investigator), who is a trained nutritionist, with support from two trained facilitators. Facilitators (nutrition graduates or health educators or graduates of development studies who have prior experience in nutrition education programs) will receive a three-day structured training program conducted two weeks prior to the first school session. The training will cover content delivery methods, facilitation skills, ethical interaction with adolescents, and session management techniques. Refresher meetings with the facilitators will also be held to review progress and ensure fidelity to the intervention protocol. The PhD student will oversee session implementation, provide ongoing mentorship to facilitators, and ensure consistency of content delivery across schools. Adherence to the intervention will be monitored using attendance checklists for each session. Additionally, two parent engagement meetings will be held (after weeks 4 and 10) to reinforce dietary messages, promote equal food distribution within households, and encourage supportive home environments. These meetings will be conducted in small groups of up to 35 parents per session, facilitated by two trained facilitators and one school teacher, and will last approximately 1.5 to 2 hours each. Parents will receive simple printed nutrition guides (the same as those used for students), suggested weekly meal plans using locally available foods, and example recipes to encourage nutritious, affordable meals at home. The sessions will be aimed solely at parents (both mothers and fathers), and students will not attend. Adherence to these meetings will be tracked through attendance checklists for both sessions. The overall approach is evidence-driven, incorporating findings from the investigators’ previous quantitative and qualitative studies, as well as stakeholder recommendations from teachers, parents, local leaders, and representatives of NGOs.