This study looks at how sugar affects people with Parkinson's Disease (PD). PD is a brain disorder that causes problems with movement, like shaking or stiffness. Some people with PD eat more sugary foods, even before showing movement problems. The study will test how sugar impacts PD symptoms and body reactions like insulin and glucose levels. Insulin is a hormone that helps control blood sugar, and glucose is a type of sugar our bodies use for energy. The study uses a special test (oral glucose tolerance test) to see how the body handles sugar. Participants will be split into two groups: those who crave sweets more and those who don't. To join, you must have PD, be between 50 and 80 years old, and be able to stop PD medicine in the morning without problems. People with diabetes or other brain diseases can't join.

• The study involves a special sugar tolerance test.
• Participants need to stop PD medication in the morning temporarily.
• Participants will be divided into two groups based on their sweet cravings.