Dietary patterns and lifestyle factors in the Norwegian EPIC cohort: The Norwegian Women and Cancer (NOWAC) study

Objective: To identify different dietary patterns in Norway using a combination of cluster and factor analysis. Design: Cross-sectional study. Setting: Nation-wide, population-based study. Subjects: The Norwegian EPIC cohort is a subcohort of the Norwegian Women and Cancer study (NOWAC), and consist 37.226 women aged 41 - 56 y who answered a food frequency questionnaire (FFQ) in 1998. Interventions: The associations among 50 food variables were first investigated by using principal component analysis. Five important factors were found. The five principal components were then used as input in the cluster analysis. Different socioeconomic and lifestyle variables were examined. Results: Six clusters of dietary patterns were found, and were labelled accordingly: ` traditional fish eaters', ` healthy eaters', ` average, less fish, less healthy', 'Western', ` traditional bread eaters', and ` alcohol users'. The traditional fish eaters and the traditional bread eaters were both highly represented in the north and west of Norway and were more likely to be present among persons with lower income and lower education. The healthy and the alcohol drinkers were found mostly in the south and east and were more likely to have higher income. Persons in the alcohol group were more likely to be current smokers. The western group had the highest percentage of three or more persons in the household and the shortest time since last birth, indicating that families with children dominate this group. Conclusion: Our data indicate six different dietary patterns in Norway, each with different socio-demographic and lifestyle characteristics.