Influence of diet quality on body composition, cardiometabolic health and weight gain in pregnancy.

Diet is key for a healthy lifestyle, yet evidence on how diet quality affects body composition and cardiometabolic health during pregnancy is insufficient. The aims of this study were to examine associations of diet quality (Swedish Healthy Eating Index (SHEI)) with body composition, cardiometabolic health in early and late pregnancy (gestational weeks 14 and 37) and gestational weight gain (GWG). This observational study used cross-sectional and prospective data from the HealthyMoms trial at two timepoints: early (n 302) and late pregnancy (n 134). Exposure was diet quality (SHEI) assessed through online 24 h recalls, and outcomes included body composition (body fatness, BMI, fat mass index (FMI)), cardiometabolic health (homeostatic model assessment for insulin resistance (HOMA-IR), metabolic syndrome (MetS) score, glycaemia) and GWG. Linear regression was used to investigate associations between SHEI and outcomes. In the cross-sectional analyses, higher SHEI was associated with lower body fatness, BMI, FMI and MetS score in early pregnancy (all B ≤ -0·14, all P ≤ 0·02). Similar results were seen in late pregnancy, with the addition of an association with HOMA-IR (all B ≤ -0·20, all P ≤ 0·008). Prospectively, higher SHEI in early pregnancy was associated with lower body fatness, BMI, FMI, glycaemia, HOMA-IR and MetS score in late pregnancy (all B ≤ -0·09, all P ≤ 0·01). There were no statistically significant associations of change in SHEI with GWG or other outcomes (P ≥ 0·09). In conclusion, a healthy diet, especially in early pregnancy, seems beneficial for body composition and cardiometabolic health. Focusing on key dietary advice, as captured by SHEI, may be advantageous and feasible within maternity care.