Development and validation of the Brazilian Dietary Guidelines Adherence Score (BraScore): a novel index to assess the adherence to the Dietary Guidelines for the Brazilian Population

Background : The Dietary Guidelines for the Brazilian Population (hereinafter referred to as the Guidelines) provide recommendations for a healthy and sustainable diet. Objective: To describe the development and validation of the Brazilian Dietary Guidelines Adherence Score (BraScore). Methods: This work involved multiple methodological steps: defining guiding principles for the development, identifying food components, setting cut-off points for scores, and assessing content validity, construct validity, and reliability. To evaluate construct validity, we used dietary intake data from the 2017-2018 Household Budget Survey. It included: the assessment of the correlation of the BraScore with total energy intake, the evaluation of the BraScore variability and the number of patterns explaining this variability through Principal Component Analysis, the ability to distinguish between population subgroups (gender, age group, income quartiles, and area of residence), and the analysis of the scores for diets developed by nutritionists. Reliability was assessed using Cronbach's Alpha. Results: The BraScore is composed of 10 components divided into three dimensions: to be consumed (legumes; fruits; vegetables; diversity), to be limited (red meat; eggs, fish, milk, and poultry; processed foods; table sugar; table salt), and to be avoided (ultra-processed foods). The BraScore ranges from 0 to 100 points, with higher scores indicating greater adherence to the Guidelines. The analyses showed weak correlation with energy intake (coefficient: -0.13). There was substantial variability among individuals (scores ranged from 28.9 to 86.2 between the 1th and 99th percentiles), with multiple patterns explaining this variability. The score distinguishes population groups (elderly individuals, people with lower income and residents of rural areas tend to have a higher BraScore) and higher scores were found for diets developed by nutritionists (ranging from 84.6 to 97.6 points). Cronbach’s Alpha was 0.53, indicating acceptable reliability. Conclusions: The BraScore achieved satisfactory performance in assessing adherence to the Dietary Guidelines for the Brazilian Population.