Validation of the Brasil-Nutri software for 24-hour dietary recall using recovery biomarkers

To evaluate measurement errors in duplicate 24-hour dietary recalls, guided by the Brasil-Nutri software, using recovery biomarkers for energy, protein, sodium, and potassium in a subsample of participants from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

Apparently healthy men and women with stable body weight were included in the study. Two non-consecutive 24-hour dietary recalls, guided by the Brasil-Nutri software, were compared with recovery biomarkers of protein, potassium, and sodium obtained from two 24-hour urine samples. Total energy expenditure was assessed using the doubly labeled water method.

Eighty individuals, aged 43 to 72 years, participated in the study. Self-reported energy intake (2,146 kcal/day) was lower than the total energy expenditure estimated by the doubly labeled water method (2,526 kcal/day), with a mean difference of 380 kcal/day. Self-reported protein intake (94.9 g/day) was higher than the biomarker estimate (87.6 g/day). For sodium, mean self-reported intake was 2.9 g/day compared with 4.7 g/day estimated by the biomarker, while potassium intake was 2.9 g/day versus 3.0 g/day, respectively.

The Brasil-Nutri software showed acceptable performance for estimating population mean intake of some nutrients; however, important measurement errors were observed, particularly for sodium intake. In addition, correlations with recovery biomarkers were low to moderate, indicating limitations in individual-level agreement.