Examining macro and micronutrient intakes in the Sri Lankan twin cohort: validation of subjective biomarkers from the COTASS-3 study

Poor dietary habits and insufficient nutrient intake pose significant global challenges. This study examines the nutrient intake of Sri Lankan adults and its association with selected socio-demographic characteristics during the economic crisis from 2020 to 2023. It also examines the validity of a subjective 24-hour dietary recall (24HDR) questionnaire using blood and urine biomarkers. Data were collected from 164 twins and 138 adult offspring of the twins in the Colombo District of Sri Lanka. Nutrient intake was calculated using a 24HDR and, then compared with the recommended dietary allowances (RDA) in Sri Lanka. Blood and urine samples were analyzed for biomarker detection to assess dietary validity. Participants did not reach the recommended energy intake (mean for females: 1954.93 Kcal; mean for males:2507.04 Kcal). Participants also failed to meet the RDA for fat and dietary fiber. However, 71% of participants achieved the recommended carbohydrate intake. Micronutrient deficits were also evident; for example, most participants had low intakes of vitamins B2, B3, B12, C, and calcium. Regression analysis comparing questionnaire-based nutrient intake with biomarker data showed positive associations between serum beta-carotene, zeaxanthin, and vitamin D intake, as well as between urinary phenolic content, serum zeaxanthin, and vitamin A intake. Age significantly influenced portion size and the intake of energy, fat, and vitamins. Our findings support the validity of the 24HDR as a dietary and nutritional assessment tool in Sri Lanka. These results offer valuable insights for public health policymakers, highlighting the importance of revising dietary recommendations to enhance dietary diversity and promote routine nutritional assessments in Sri Lanka.