Ultra-processed Foods and Diet Quality in Association With Long-term Weight Change and Progression to Type 2 Diabetes Among Individuals With a History of Gestational Diabetes Mellitus—A Prospective Study

OBJECTIVE We examined the associations of overall and group-specific ultra-processed food (UPF) consumption with long-term weight change and type 2 diabetes (T2D) progression following gestational diabetes mellitus (GDM)-complicated pregnancies. RESEARCH DESIGN AND METHODS We included 4,207 women with a history of GDM from the Nurses' Health Study II (1991–2021). UPF intake (servings/day) was assessed via food frequency questionnaires every 4 years and quantified per the NOVA classification. Diet quality was evaluated using the Alternate Healthy Eating Index-2010 (AHEI). Associations between UPF intake changes and weight changes (kg) were assessed using generalized estimating equations (GEE) (n = 3,781). Cox regression models estimated adjusted hazard ratios (HRs) and 95% CIs of habitual UPF intake modeled by time-updated cumulative averages with T2D risk. Joint associations of UPF and AHEI with weight change and T2D risk were examined using the same GEE and Cox regression models, respectively. RESULTS T2D developed in 1,040 participants. Increased UPF consumption was associated with greater weight gain (P-trend < 0.0001; quartile [Q]1 vs. Q4: 0.52 kg vs. 1.65 kg). Habitual UPF consumption was positively associated with T2D risk: adjusted HRs (95% CIs) for Q1 to Q4 were 1.00 (ref), 1.07 (0.87, 1.32), 1.25 (1.03, 1.53), and 1.20 (0.99, 1.46), respectively (P-trend = 0.04). These associations persisted in women with higher AHEI scores. When modeling UPF and AHEI jointly, only women with stable or decreased UPF intake and increased AHEI achieved 4-year weight maintenance. CONCLUSIONS In women with a history of GDM, UPF consumption was associated with weight gain and higher T2D risk, even among those with higher diet quality.