Estimated protein intake by 24-hour urine: validation study

• Grant number: 19/22194-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2020
• End date: December 31, 2020
• Field of knowledge: Health Sciences - Nutrition - Nutritional Analysis of Population
• Principal Investigator: Dirce Maria Lobo Marchioni
• Grantee: Letícia Lopes Takarabe
• Host Institution: Faculdade de Saúde Pública (FSP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The assessment of food consumption is of utmost importance in nutrition science, however existing food surveys are subject to variation and measurement errors. Recognizing the limitation in obtaining accurate measurements of food consumption, it is necessary to validate these tools. 24-Hour Urinary Nitrogen is a biomarker used to test the validity of protein intake estimates obtained from the 24-Hour Food Recall (R24h), which is a self-reported method of food intake. Objective: The aim of this project is to estimate the protein consumption measurement error associated with the 24-hour Food Recall applied by both the Brazilian version of GloboDiet and Brasil-Nutri softwares through a validation study with urinary nitrogen. Methodology: This study was conducted with participants from the third wave of the Longitudinal Study of Adult Health (ELSA-Brasil) at the University Hospital of the University of São Paulo. Will be included 100 individuals aged between 35 and 75 years of both sexes. Will be collected 24-hour Food Record (R24h), one with each software; Food Frequency Questionnaire (FFQ); two 24-hour urine samples; A General Characterization Questionnaire is conducted, which includes lifestyle and socioeconomic status habits of each participant. Usual protein intake will be determined from the average urinary nitrogen, calculated by 24-hour urea, and R24h estimates. Agreement between measurements will be tested by mean difference, linear correlation, Kappa statistics and Bland-Altman graphs.