Obesity is a public health concern and cardiometabolic consequences are severe when obesity develops during youth and continues into adulthood. Treatment prior to adulthood confers health benefits, but adolescent obesity rates have continually increased, reaching 20.6% in 2013-2014. Quality and quantity of dietary intake contribute to the development of obesity, but limitations of self-reported dietary intake are evident in overweight or obese adolescents, who frequently misreport nutrients of concern. Added sugar, sodium, and protein intake may indicate diet quality in this population. The 2015-2020 Dietary Guidelines recommend decreasing consumption of added sugars, sodium, and processed protein due to their known contributions to overweight and obesity. Objective dietary intake assessment measures are necessary for investigating the association between dietary intake and health outcomes. Added sugar, sodium, and protein intake could be assessed objectively with a panel of urinary biomarkers. Prior research indicates the potential of these urinary biomarkers to reflect dietary intake, but to date, no controlled feeding study has been conducted in adolescents. Using a controlled feeding design, the current study aims to evaluate the validity of urinary sucrose, fructose, sodium, and nitrogen as objective indicators of dietary intake. It is hypothesized that urinary sucrose and fructose will reflect dietary added sugar intake, while urinary sodium and nitrogen will correspond to dietary sodium and protein intake, respectively, in a healthy adolescent population. These biomarkers, if valid, could be used in clinical and epidemiological research to improve understanding of the associations between dietary intake and health outcomes.