Measuring Cowpea Consumption in Young Children and Pregnant Women in Ghana

Current dietary assessment methods rely on self-report food intake such as food frequency questionnaires, 24-hr dietary recall, or diet diaries, and the prevalence of misreporting with these tools is estimated at 30-88%.A reliable and convenient way to measure the quantity of cowpea consumed by an individual. The hope is to identify a novel set of dietary biomarkers that will measure cowpea consumption, be free from participant recall bias, and serve to quantify legume intake. A total of 40 subjects, 20 children (9-21 months) and 20 pregnant women (>18 yr) will consume 3 distinct daily intake dosages of cooked cowpeas with the daily intake increased every 5 days. Urine samples will be collected 3 times during each 5-day period and blood spots will be collected during a washout period and at the end of the final 5-day period. Urine samples will undergo metabolite detection via ultra-performance liquid chromatography tandem mass spectrometry in positive and negative ion mode. Peaks are quantified using area-under-the-curve (AUC) and each metabolite is quantified in terms of its median-scaled relative abundance for the metabolite across the entire data set. A repeated measures 2-way ANOVA will be used to compare cowpea metabolite abundances over time and with respect to variation in an individual baseline levels.