In a two-dimensional, cross-over meal study, 12 healthy volunteers consumed in a randomized sequence four test meals: chicken, pork, beef, and a control made of egg white and pea. At the same time they were independently randomized to four starchy foods to be consumed together with the meats: boiled potatoes, fried potatoes, potato crisps or boiled white rice. Fasting and postprandial urine samples were collected to cover 48 h after each meal and samples were profiled by untargeted LC-ESI-qTOF-MS metabolomics. The profiles following the meal challenges were explored by univariate and multivariate analyses and single and combined markers of intake identified chemically by MS/MS fragmentation experiments and statistically by ROC curves and error rates as well as FDR statistics.
This cross-over meal study is a four-way intervention with 12 volunteers randomized at the same time to four meals with fried meats (beef, pork, chicken and amino-acid matched non-meat control) and to four meals with potato products (boiled, chips, fries, and a control with boiled white rice) to search for biomarkers of intake.