Stability of dietary patterns in young women over a 2-year period.

OBJECTIVE: To examine the stability of dietary patterns in young women over a two-year period and to identify factors that influence stability.
DESIGN: A food frequency questionnaire was used to assess diet. In a subgroup, this was repeated after 2 years. Questions were asked about major changes to diet over this time. Dietary patterns were identified using principal components analysis and pattern scores were compared at the two time points. The consumption of foods was also examined. The relationship between change in pattern scores and socio-demographic factors and body mass index was assessed.
SETTING: The Southampton Women's Survey, a prospective study of diet, health and lifestyle in young women and their influences on fetal growth.
SUBJECTS: A subgroup of 94 women from a cohort of 6129 nonpregnant women aged 20-34 years.
RESULTS: Two dietary patterns, labelled 'prudent' and 'high energy', were identified. Spearman correlation coefficients between the initial and repeat scores for the prudent and high-energy patterns were 0.81 and 0.64, respectively. Average changes (repeat - initial) were 0.13 and -0.01 SD of initial score. Change in prudent dietary pattern score was influenced by amount of strenuous exercise taken and by changes in partnership status. An increase in high-energy pattern score was associated with lower social class.
CONCLUSIONS: Dietary patterns in young women are reasonably stable over a 2-year period. This suggests that dietary patterns identified in the recent past may provide useful information about current dietary patterns.