Development, Validation, and Use of a Semi-Quantitative Food Frequency Questionnaire for Assessing Protein Intake in Papua New Guinean Highlanders

ObjectivesThe aim of this article was to develop a semi-quantitative food frequency questionnaire (FFQ) and evaluate its validity to estimate habitual protein intake, and investigate current dietary protein intakes of Papua New Guinea (PNG) Highlanders. MethodsA 32-item FFQ was developed and tested among 135 healthy male and female volunteers. The FFQ-estimated daily total and animal protein intakes were compared with biomarkers and 3-day Weighed Food Records (WFR) by correlation analyses, Bland-Altman plot analyses and joint classification analyses. ResultsThe FFQ-estimated total protein intake significantly correlated with urinary nitrogen in the first morning void after adjusting urinary creatinine concentration (r=0.28, P<0.01) and the FFQ-estimated animal protein intake significantly correlated with the hair N-15 (Spearman's r=0.34, P<0.001). The limits of agreement were 2.39 Z-score residuals for total protein intake and +/- 2.19 Z-score for animal protein intake, and intra-individual differences increased as protein intake increased. The classification into the same and adjacent quartiles was 66.0% for total protein intake and 73.6% for animal protein intake. Median daily total and animal protein intake estimates from the FFQ and the 3-day WFR showed a good agreement with differences of 0.2 and 4.9 g, respectively. None of the studied communities in the PNG Highlands met the biologically required protein intake; although the community closer to an urban center showed higher protein intake than the more remote communities. ConclusionsThe newly developed 32-item FFQ for PNG Highlanders is applicable for evaluation of protein intake at the individual level. Am. J. Hum. Biol. 27:349-357, 2015. (c) 2014 Wiley Periodicals, Inc.