Comparison in dietary patterns derived for the Canadian Newfoundland and Labrador population through two time-separated studies.

Background: While a dietary pattern is often believed to be stable in a population, there is limited research assessing its stability over time. The objective of this study is to explore and compare major dietary patterns derived for the Canadian subpopulation residing in Newfoundland and Labrador (NL), through two time-separated studies using an identical method.

Methods: In this study, we derived and compared the major dietary patterns derived from two independent studies in the NL adult population. The first study was based on the healthy controls from a large population-based case-control study (CCS) in 2005. The second was from a food-frequency questionnaire validation project (FFQVP) conducted in 2012. In both studies, participants were recruited in the same manner and dietary information was collected by an identical self-administered food-frequency questionnaire (FFQ). Exploratory common factor analysis was conducted to identify major dietary patterns. A comparison was conducted between the two study populations.

Results: Four major dietary patterns were identified: Meat, Vegetables/fruits, Fish, and Grains explaining 22%, 20%, 12% and 9% variance respectively, with a total variance of 63%. Three major dietary patterns were derived for the controls of the CCS: Meat, Plant-based diet, and Fish explaining 24%, 20%, and 10% variance respectively, with a total variance of 54%. As the Plant-based diet pattern derived for the CCS was a combination of the Vegetables/fruits and Grains patterns derived for the FFQVP, no considerable difference in dietary patterns was found between the two studies.

Conclusion: A comparison between two time-separated studies suggests that dietary patterns of the NL adult population have remained reasonably stable over almost a decade.