This study explores how two different diets affect people with Parkinson's Disease (PD) over 18 months. **Parkinson's Disease** is a brain disorder that causes shaking, stiffness, and difficulty with balance and coordination. The **Mediterranean diet** includes lots of fruits, vegetables, and healthy fats, and might help lower the risk of PD and improve symptoms by affecting the gut, where food is digested. Participants will be randomly assigned to follow either a Mediterranean-style diet or a standard diet. They will attend in-person visits at the University of British Columbia (UBC) and participate in online activities like diet coaching and cooking classes.

• This study lasts 18 months and involves 6 in-person visits at UBC.
• Participants will be given a wrist device to track physical activity and lifestyle.
• Eligibility requires a stable PD diagnosis, no dementia, and internet access.