Development and Validation of a Culture-Specific Dietary Assessment Tool for Evaluating Diet Quality Among Adults in South South Nigeria

Accurate dietary assessment in Nigerian populations requires tools that reflect local food culture, seasonality, and preparation methods. Existing standardised instruments developed in Western contexts often fail to capture the diversity and complexity of South South Nigerian diets, limiting their validity and utility. This study developed and validated a culture-specific dietary assessment tool for evaluating diet quality among adults in South South Nigeria, with field trials conducted in Cross River, Rivers, and Delta States. A systematic tool development process was followed including food listing using multiple 24-hour recalls across seasons, expert panel review, cognitive interviews with target population members, and pilot testing with 150 adult participants. Convergent validity was assessed against a reference 3-day weighed food record, and test-retest reliability was evaluated over a two-week interval. Internal consistency was assessed using Cronbach's alpha. Results showed strong test-retest reliability with intraclass correlation coefficients exceeding 0.75 for all food groups. Convergent validity analysis demonstrated moderate to strong correlations between tool-derived nutrient estimates and the reference method for energy, protein, iron, and vitamin A. The final tool comprised 120 food items specific to South South Nigerian cuisine organised into culturally meaningful food groups. The study recommends adoption of the validated tool for dietary surveillance and research in the region. Keywords: dietary assessment tool, validation, diet quality, South South Nigeria, culturally adapted