Change in Diet Quality and Dietary Intake From Pregnancy to 1-Year Postpartum: A Longitudinal Analysis in Australian Women.

Objective: This longitudinal analysis in Australian women evaluated change in diet quality and food and nutrient intakes from the third trimester of pregnancy to 1-year postpartum with comparison to national nutrition recommendations. Associations between diet quality, sociodemographic and health characteristics were also investigated.

Methods: This study was an analysis of data from the ORIGINS pregnancy cohort (2017-2023). Participants included were those with complete dietary data at both timepoints, aged ≥ 19 years, and not pregnant 1-year postpartum. Dietary intake was assessed using the Australian Eating Survey food frequency questionnaire, and diet quality using the Australian Recommended Food Score (ARFS). Participants self-reported sociodemographic data, and health data were obtained from hospital medical records. Paired sample t-tests analysed change in diet quality and dietary intake, and linear regression estimated associations between maternal characteristics and diet quality. Food group and nutrient intakes were compared to recommendations in the Australian Guide to Healthy Eating and Nutrient Reference Values.

Results: Of 337 women (33.1 (4.5) years, 49.9% Australian-born, 51.3% university educated), mean (95% CI) diet quality was suboptimal during pregnancy and 1-year postpartum (ARFS 34.0 (33.0, 35.0) vs. 34.8 (33.8, 35.8) points out of 73, p = 0.038). Higher serves of vegetables and meat, energy intake from protein, and intake of retinol equivalents, and less fruit, dairy, carbohydrate, saturated fat, iodine and folate were consumed 1-year postpartum (p < 0.05). Alignment with recommendations was low during pregnancy and 1-year postpartum for food groups, macronutrients and key micronutrients. Lower diet quality during and after pregnancy was linked to not having had a university education, and a higher pre-pregnancy BMI. Postpartum, younger age and lower income was also associated with poorer diet quality and having a BMI in the overweight category before pregnancy (p < 0.05).

Conclusion: These findings highlight persistent nutritional inadequacies and social disparities, and the urgent need for targeted, evidence-based nutrition interventions to improve diet quality and nutrient intakes in pregnant and postpartum women, particularly younger women with lower education and income, and those with a higher pre-pregnancy BMI.