Which Combined Profiles of Physical Activity and Dietary Intake Are Associated with Postpartum Prediabetes Status Among Women with Prior Gestational Diabetes Mellitus in Underserved Rural Areas of Central South China?

Background/Objectives: Women with prior gestational diabetes mellitus (GDM) are at higher risk for prediabetes, particularly when inactivity or poor diet persists after childbirth. These behaviors often co-occur, and their combined effect is greater than the sum of individual risks. This study aimed to identify physical activity and dietary profiles among women with prior GDM in underserved areas, examine their association with impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and investigate their associated factors. Methods: A cross-sectional analysis of baseline data collected in July 2018 and November 2022 from two randomized controlled trials was conducted (n = 633). Activity, dietary intake, glucose levels, and socio-demographic, anthropometric, and psychosocial characteristics were collected. Latent profile analysis identified behavior profiles. Binary and multiple logistic regressions assessed associations and influencing factors. Results: Three distinct profiles were identified including “Less Activity and Low Dietary Fiber Intake group”, “Adequate Activity but Low Dietary Fiber Intake group”, and “Adequate Activity but High Starch Intake group”. Compared with the “Adequate Activity but Low Dietary Fiber Intake group”, the “Less Activity and Low Dietary Fiber Intake group” had increased IFG risk (odds ratio OR, 3.792; 95% CI, 1.146–12.543); women with non-precarious employment, no family history of diabetes, or inadequate external environmental resources were more likely in this group. “Adequate Activity but High Starch Intake group” had higher IFG (OR, 6.321; 95% CI, 1.500–26.639) and IGT (OR, 6.030; 95% CI, 1.530–23.770) risk; women with family income <416 USD/month or worse psychological health tended toward this group. Conclusions: Unhealthy behavior profiles were observed among women with prior GDM. High starch intake and insufficient activity were associated with greater prediabetes risks. Screening and education on physical activity and diet may warrant particular attention among women with non-precarious employment, low family income, or no family history of diabetes. In addition, integrating strategies that enhance psychological health and improve external environmental resources into lifestyle-related interventions may represent a promising approach.