Major dietary patterns of young and middle aged women: results from a prospective Australian cohort study

The aim of this study was to assess the major dietary patterns of two age cohorts of women, to determine to the extent to which the dietary patterns differ between the cohorts and to assess whether they vary according to sociodemographic and behavioural characteristics and patterns of nutrient intake.

Dietary intake was assessed using an 80-item food frequency questionnaire for women aged 50-55 years (n=10 150; 'middle age') in 2001 and aged 25-30 years (n=7371; 'young') in 2003, from the Australian Longitudinal Study on Women's Health. Factor analysis using principal component extraction was used to identify dietary patterns, and a pattern score was calculated from the consumption of the food items identified with each dietary pattern. Associations between the dietary pattern scores and sociodemographic and behavioural characteristics and nutrient intakes were investigated using regression analysis.

Six dietary patterns were identified and were labelled: cooked vegetables; fruit; Mediterranean-style; processed meat, meat and takeaway; reduced fat dairy; and high-fat and sugar foods. Regression analysis revealed that healthier dietary patterns were significantly associated with other favourable health-related behaviours, higher socioeconomic status and living in urban areas (P-values <0.05).

In spite of differences in the level of consumption of individual food items, the similarity in dietary patterns across two generations of women suggests that policies and interventions to improve diet should focus on social and economic factors and general health-related behaviour rather than different age groups.