Protein Intake Estimated by Weighed Diet Records in Patients with Type 2 Diabetes: Misreporting and Intra-Individual Variability Using 24-Hour Nitrogen Output as Criterion Standard

• Published in: Journal of the American Dietetic Association Vol. 108; no. 5; pp. 867 - 872
• Main Authors: dos Santos Vaz, Juliana, RD, Bittencourt, Miriam, RD, Almeida, Jussara Carnevale, RD, Gross, Jorge Luiz, MD, PhD, De Azevedo, Mirela Jobim, MD, PhD, Zelmanovitz, Themis, MD, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.05.2008; Elsevier Limited
• Subjects: 24-hour nitrogen output; accuracy; Biomarkers - urine; blood glucose; Body Mass Index; Confidence Intervals; Cross-Sectional Studies; Diabetes; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - diet therapy; Diabetes Mellitus, Type 2 - metabolism; Diabetic Nephropathies - etiology; Diabetic Nephropathies - prevention & control; Diet; diet recall; Diet Records; dietary protein; Dietary Proteins - administration & dosage; Dietary Proteins - metabolism; Dietary Proteins - urine; estimation; Female; food records; Gastroenterology and Hepatology; Glycated Hemoglobin A - analysis; Humans; Internal Medicine; Logistic Models; Male; Middle Aged; Multivariate Analysis; Nitrogen; Nitrogen - urine; nitrogen balance; noninsulin-dependent diabetes mellitus; Nutrition; Nutrition Assessment; Odds Ratio; patients; protein intake; Proteins; Self Disclosure; Sex Factors; variance; Weight control
• ISSN: 0002-8223; 2212-2672; 1878-3570; 2212-2680
• DOI: 10.1016/j.jada.2008.03.022

Abstract In patients with type 2 diabetes mellitus (DM), the factors associated with under- or overreporting of protein intake in nutrition assessment tools, as well as the variability of diet records, have not been fully established. The aim of this cross-sectional study was to evaluate factors associated with under- or overreporting of protein intake and its variability in patients with type 2 DM. Protein intake was estimated in 205 patients (aged 59.8±9.6 years) using 3-day weighed diet records and 24-hour nitrogen output (criterion standard). Twenty-three patients repeated the 3-day weighed diet records three times. Clinical, nutrition, and lifestyle evaluations were performed. Coefficients of variation were calculated for protein intake. Factors associated with under- and overreporting were assessed using multivariate logistic regression models. Coefficients of variation for protein intake estimated by weighed diet records or nitrogen output were similar (11.9% vs 11.3%; P >0.05). Using Beaton's formula, a difference of 16.5% in protein intake between two 3-day weighed diet records was acceptable. The lowest A1c test tertile (≤6.9%) was associated with protein intake underreporting (odds ratio [OR]=0.40; 95% confidence interval [CI]=0.16 to 0.99; P =0.046] after adjustment for sex, age, employment status, and living alone. Male sex (OR=6.66; 95% CI: 2.08 to 22.07; P =0.002), A1c test (OR=1.29; 95% CI: 1.02 to 1.64; P =0.036), and body mass index (OR=0.89; 95% CI: 0.80 to 0.994; P =0.039), adjusted for physical and employment status, education, and preparing one's own meals, were associated with overreporting. In conclusion, in patients with type 2 DM, a difference >16.5% in protein intake between two 3-day weighed diet records should be interpreted as a true discrepancy. Poor glucose control and male sex increase the chance of inaccurate 3-day weighed diet records.