Stress and Depressive Symptoms Are Not Associated with Overall Diet Quality, But Are Associated with Aspects of Diet Quality in Pregnant Women in South Carolina

Background: Poor mental health may hinder diet quality in pregnancy.

Objective: This study 1) examined whether stress and depressive symptoms are associated with diet quality (via Healthy Eating Index [HEI] 2015 total scores and dietary intake of food groups/nutrients that align with HEI-2015 components) and 2) tested race as a moderator in the relationship between mental health and diet quality.

Design: This was a cross-sectional analysis of baseline data from a randomized controlled trial collected January 2015 through January 2019 in Columbia, South Carolina. Trained staff administered demographic and psychosocial questionnaires and conducted anthropometric measures. Participants completed two 24-hour dietary recalls, which were self-administered (one on-site, one at home).

Participants: The Health in Pregnancy and Postpartum study was a randomized controlled trial targeting excessive gestational weight gain among pregnant women with overweight/obesity (N = 228).

Main outcome measures: The HEI-2015 total scores and food groups/nutrients that align with HEI-2015 were calculated.

Statistical analyses performed: Multiple linear regression models were used to estimate the relationship between mental health and HEI-2015 total scores and dietary intake of food groups or nutrients that align with HEI-2015 components. Multiplicative interaction terms of stress or depressive symptoms with race were used to determine moderation.

Results: Participants' diet quality was suboptimal (M = 52.0 ± 11.7; range, 27-85). Stress was negatively associated with HEI-2015 total scores (crude but not adjusted model). Stress scores were positively associated with consumption of dairy, refined grains, and added sugars and negatively associated with total protein foods. Depressive symptoms were positively associated with consumption of dairy, refined grains, and saturated fats. Race was not a moderator.

Conclusions: Diet quality was poor overall, but stress and depressive symptoms were not associated with HEI-2015 total scores in adjusted models. Excluding dairy, stress and depressive symptoms were associated with the consumption of food groups or nutrients related to worse diet quality. These relationships should be examined longitudinally to help establish causality and inform future interventions.