Dietary intake and processes of behaviour change in a nutrition education intervention for pregnant women in rural Malawi: a cluster-randomised controlled trial

摘要

Objective: To examine if increased intake of locally available nutrient-dense foods among pregnant women improved the quality of their dietary intake and if use of the Theory of Planned Behaviour could explain changes in their dietary behaviour. Design: We used data from a randomised controlled trial where the intervention group received nutrition education and dietary counselling. We promoted the use of recipes that utilised powders to enhance dietary diversity. We examined how the intervention achieved changes in dietary intakes and used mixed effects logistic regression models with random effects at village level to explore changes over time of the outcomes, adjusted for selected explanatory variables. Setting: The study was conducted in twenty villages in rural Malawi. Participants: Data from 257 pregnant women who were enrolled during late first trimester and followed until birth. Results: The intervention achieved improvements in the Dietary Diversity Score (DDS) and the Six Food Group Pyramid (SFG) score, especially in intakes of micronutrient-rich foods. A third of the women in the intervention group attained optimal DDS, whereas about 50 % attained optimal SFG. The theorised behaviour mediators (i.e. nutrition attitudes, nutrition behaviour control and subjective norm) that had improved were also significantly associated with high DDS. Conclusions: Improved dietary intakes were achieved through promoting the use of locally available nutrient-dense foods. Attainment of high DDS was a consequence of the women's belief in the effectiveness of the proposed nutrition recommendations. We identified critical personal and environmental constraints related to dietary intakes during pregnancy in a low-resource setting.