Steinemann , Nina, Leticia Grize, Katrin Ziesemer, Peter Kauf, Nicole Probst-Hensch, and Christine Brombach. “Relative Validation of a Food Frequency Questionnaire to Estimate Food Intake in an Adult Population”. Food & Nutrition Research 610 (March 29, 2017). Accessed April 7, 2026. https://foodandnutritionresearch.net/index.php/fnr/article/view/1165.