Background and objectives   Adopting a plant-based diet with limited animal-source foods can reduce non-communicable diseases and food sector emissions. Managing Type 1 diabetes (T1D) adds complexity to following dietary advice. A person-centred approach, focusing on the individual rather than the disease and partnership as a core component of care, is beneficial but challenging for healthcare professionals to implement consistently.  The Diabetes Intervention involving person-centred Nutritional Education (DINE trial) aims to evaluate the efficacy of a pre-assessed nutritional education compared to standard care and short dietary information for adults with T1D. The study will examine the intervention's impact on glucose levels, diet, lipids, and blood pressure.     Methods   The DINE trial is a non-blinded, randomised study in Sweden. The primary hypothesis is that a person-centred nutritional education has an impact on glucose time in range for adults with T1D. Fifty-four adults, ≥18 years, with T1D >12 months and an HbA1c level >57 mmol/mol will be enrolled. Data collection includes food diary, food frequency questionnaire, glucose measured by continuous glucose monitoring (CGM), Hba1c, lipids, blood pressure, food enjoyment, height and weight, measured at baseline and at six months (See Figure). The intervention group will receive an individual pre-assessment focused on partnership in care, followed by a nutritional education programme and co-creation of health plans with a dietitian. Results   Recruitment started in May 2025, and the intervention will run during 2025/2026. Differences in CGM metrics, HbA1c, lipids, blood pressure, dietary patterns and food enjoyment, from baseline to study endpoint at six months will be investigated between intervention and control group.   Conclusions   Adults with T1D will gain essential knowledge about healthy, and environmentally friendly eating and achieve better blood glucose management through person-centred approaches. Furthermore, they may improve their understanding of the lifestyle choices that can prevent future diabetes-related complications.