BackgroundIntensive lifestyle interventions were effective to reduce the risk of type 2 diabetes mellitus (T2DM) for women with gestational diabetes mellitus (GDM) history. However, reaching these mothers and maintaining participation in lifestyle interventions is suboptimal in real-world settings. Effective, feasible and sustainable new lifestyle interventions are needed. The objectives of this three-arm trial are to (1) compare diabetes risk outcomes of an evidence-based intensive lifestyle modification (ILSM) intervention, a camp-style lifestyle modification program (CAMP) intervention, and usual care among women with GDM history; and (2) evaluate the comparative efficacy of the CAMP versus ILSM intervention on implementation outcomes.MethodsA three-arm cluster randomized clinical trial (RCT) using a hybrid type 2 implementation design will be conducted in two counties in Hunan province in China. Six towns from each county will be randomly selected and assigned to CAMP, ILSM, and the usual care group (25 women from each of 12 towns, 100 women in each arm). The ILSM includes six biweekly in-person sessions and 3-month telephone health consultations, while the CAMP consists of a 2-day camp-based session and 3-month health consultations via a popular social media platform. Both interventions share the same session content, including six lifestyle skills. Efficacy (T2DM risk score and behavioral, anthropometric, psychosocial, and glycemic variables) and implementation outcomes (recruitment, acceptability, feasibility, fidelity, and cost-effectiveness) will be collected at baseline, 6-month, and 12-month. Pre-planned ANOVA F-test and generalized estimating equations will be included to test time-by-arm interactions.DiscussionThe CAMP intervention is expected to have better reach, better attendance, and comparable effectiveness in reducing the risk of T2DM, thus improving postpartum care for GDM in China. The delivery of a concentrated format supplemented with technology-based support may provide an efficient and effective delivery model for implementing maternal health promotion programs in primary care settings.Trial registrationRegistered in the Chinese Clinical Trial Registry (ChiCTR2200058150) on 31st March 2022.