Community-Based Plant-R protein Diet Education Intervention: Design, Implementation, Evaluation

Thesis Abstract

The escalating burden of diet-related non-communicable diseases in urban communities necessitates scalable, culturally appropriate nutrition interventions that increase plant-based protein intake while ensuring dietary adequacy and acceptability. This study assesses the design, implementation, and evaluation of a community-based Plant-R protein Diet Education Intervention aimed at promoting plant-derived protein sources (e.g., legumes, nuts, seeds, whole grains) as alternatives to animal-based proteins without compromising protein quality or cultural relevance. The aim is to co-create an evidence-informed education program that improves knowledge, attitudes, and dietary practices, and to evaluate its effectiveness in real-world community settings. Specific objectives are (1) to identify barriers and facilitators to plant-R protein adoption within diverse urban households; (2) to develop a theory-driven education intervention anchored in the Social Cognitive Theory and the Health Belief Model; (3) to implement the intervention in three urban communities with varying socio-economic profiles; (4) to evaluate changes in dietary intake of plant-R proteins, overall protein adequacy, and nutritional biomarkers; and (5) to assess feasibility, acceptability, and scalability for broader dissemination. A mixed-methods design is employed, combining a quasi-experimental, non-equivalent control group pretest-posttest design with a concurrent qualitative component. The study population comprises adults aged 19–65 years from three urban neighborhoods in a metropolitan region, with a target sample of 600 participants (300 intervention, 300 control) for quantitative assessment, and 40–60 purposively selected participants for in-depth interviews and focus groups. Data collection instruments include a validated semi-quantitative Food Frequency Questionnaire (FFQ) tailored to plant-R protein sources, 24-hour dietary recalls (three non-consecutive days), a nutrition knowledge and attitudes survey, and anthropometric measurements. Biomarkers such as serum albumin and ferritin will be measured in a subsample of 120 participants to assess protein status and iron stores. The intervention comprises eight weekly sessions delivered through community centers, supplemented by culturally tailored print and digital materials, cooking demonstrations, and peer-led support groups. Intervention delivery is guided by Social Cognitive Theory constructs (observational learning, self-efficacy, outcome expectations) and Health Belief Model components (perceived susceptibility, severity, benefits, barriers). Process evaluation tracks reach, dose, fidelity, and participant engagement using mixed-methods logs and facilitator checklists. Quantitative data will be analyzed using difference-in-differences models and repeated-measures ANOVA to compare pre- and post-intervention outcomes between groups, with multivariate regression adjusting for covariates (age, gender, income, baseline diet quality). Mediation analyses will test whether changes in knowledge and self-efficacy mediate dietary improvements. Qualitative data will undergo thematic analysis using a grounded theory approach to identify emergent themes related to cultural acceptability, perceived barriers, and social dynamics influencing plant-R protein uptake. An integrated mixed-methods synthesis will triangulate findings to elucidate mechanisms of behavior change and contextual determinants. Expected findings include statistically significant increases in plant-R protein intake (mean daily grams), improved overall protein adequacy (as measured by estimated daily protein intake relative to recommended dietary allowances), and favorable shifts in knowledge, attitudes, and self-efficacy regarding plant-based protein foods. Biomarker analyses are anticipated to show stable or improved iron status among participants with higher plant-R protein consumption, facilitated by increased intake of iron-enhancing plant foods and vitamin C-rich accompaniments. The study will contribute methodological insights into designing community-based nutrition education that aligns with local foodways while leveraging behavior change theory to achieve measurable improvements in dietary patterns at scale. Theoretically, the research advances knowledge by operationalizing an integrative framework that combines Social Cognitive Theory with the Health Belief Model in a community nutrition education context focusing on plant-based protein transitions. Practically, it offers a replicable design for urban settings, with explicit guidelines for curriculum development, stakeholder engagement, and scalable delivery mechanisms. Policy implications include evidence to support community-based nutrition promotion as a cost-effective strategy for improving diet quality and protein adequacy, informing guidelines for national dietary transitions toward sustainable protein sources. Recommendations emphasize strengthening partnerships with local food suppliers, integrating plant-R protein modules into existing community programs, and conducting longitudinal follow-up to assess sustained dietary change and health outcomes.