Validation of a Food Propensity Questionnaire for the Hellenic National Nutrition and Health Survey (HNNHS) and Results on This Population’s Adherence to Key Food-Group Nutritional Guidelines

Background: Food propensity questionnaires (FPQs) are means of dietary assessment in nutritional epidemiology, which provide valuable information for long term intakes and food group consumption. These tools, however, may be subjected to misreporting and need to be validated against standard quantitative methods. Aim: The aim of this study was to examine the validity of the qualitative FPQ developed to assess the dietary habits of the general population in Greece during the Hellenic National Nutrition and Health Survey (HNNHS) and to assess the population’s intake of specific food groups in relation to guidelines. Methods: Validation analysis was based on 3796 [1543 men (42.82%) and 2253 women (57.18%)] participants of the HNNHS in relation to two interviewer-administered 24 h recalls (24 hR). Participants were asked to report the frequency of their dietary intake, using the FPQ provided. Correlations and significance between methods were assessed via Spearman correlation and a Two-sample Wilcoxon rank-sum (Mann-Whitney) test, respectively. Agreement between the FPQ and the 24 hR was performed using the Bland–Altman test and differences between the FPQ’s shown intakes and the recommended intakes by the Dietary Guidelines for Greek Adults were calculated. Results: Medium to weak correlations, but statistically significant (p < 0.05), were observed for most food groups between 24 hR and the FPQ; medium for fruits, dairy products, drinks, and spirits (ranging from ρ = 0.371 to ρ = 0.461; highest for drinks and spirits) and weak for vegetables, meat, fish, eggs, starch foods, sweets, nuts, fats and oils, and fast food (ρ = 0.111 to ρ = 0.290; lowest for starch foods). A non-significant correlation was found for legumes (ρ = 0.070). The mean intake agreement (Bland–Altman analysis) between the FPQ and the 24 hR was 96.08% and ranged from 94.43 to 99.34% for the 14 food groups under examination. When food group intakes were compared to guidelines, results showed that the population’s dietary intake was below the guidelines for fruits, vegetables, whole grains, fish, and legumes. On the other hand, it was above the guidelines for most of the “unhealthy” food groups, in particular, fast food, sweets, drinks and spirits, red meat, and sweets. Conclusions: The specific FPQ provides valid information on major food groups and can be used to examine long term dietary patterns in nutritional studies. Ιn addition, dietary intakes of Greek adults are problematic and initiatives at the public health level are necessary.