Measurement of dietary intake of fatty acids in pregnant women: comparison of self-reported intakes with adipose tissue levels.

PURPOSE

Dietary fatty acids affect several pregnancy outcomes including fetal growth and development. We compared self-reported intakes with concentrations of fatty acids in adipose tissue in pregnant women.

METHODS

The study was nested within Geração XXI, a birth cohort assembled in Portugal. Intake was assessed by nine food diaries (FDs) completed throughout pregnancy and an FFQ administered in the immediate postpartum period. A gluteal adipose tissue sample was obtained from 23 women.

RESULTS

FDs and FFQ estimated similar percentages of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA), but the adipose tissue yielded a lower percentage of SFA and higher percentages of MUFA and PUFA. Correlations between FDs and adipose tissue ranged from r = 0.50 for trans fatty acids to r = -0.19 for linolenic acid. The proportion of women categorized in opposite tertiles by these two methods ranged from 4.3% to 30.4%. Correlations between FFQ and adipose tissue were even weaker and levels of misclassification higher.

CONCLUSIONS

The correlations observed in this study between self-reported intakes and tissue concentrations are weaker than those observed in a similar study conducted among nonpregnant women, suggesting that adipose tissue levels of fatty acids may be a poor biomarker of dietary intake in pregnancy.