Weight Loss and Appetite Changes in Parkinson's Disease

Prevalence and Timing of Weight Changes

Weight loss is a key feature of Parkinson's disease and patients have significantly lower BMI than healthy controls 1, 2, 3
Weight loss may be present at diagnosis and is associated with disease progression 3, 4
Approximately 15% of community-dwelling PD patients are malnourished, with another 24% at medium or high risk of malnutrition 2, 4
Weight changes can occur throughout the disease course, with weight loss becoming more prominent as the disease advances 3, 5

Increased energy expenditure due to rigidity, tremor, and dyskinesias is a major contributor to weight loss 3, 4
This increased expenditure is often not compensated by increased energy intake 3, 6
Dysphagia affects 60-80% of patients, particularly in advanced disease 2, 4
Impaired gastrointestinal motility and gastroparesis affect nutrient intake 1

Weight loss is not benign and requires monitoring and intervention 3, 4
Malnutrition is associated with increased disease severity 3, 6
Body weight should be monitored throughout disease progression 2, 3
Nutritional assessment should be conducted at least yearly and whenever clinical conditions change 3, 4
Vitamin status (particularly vitamin D, B12, and folate) should be regularly assessed 3, 6

Levodopa therapy is associated with side effects that can impact appetite and weight, including nausea, vomiting, anorexia, and gastrointestinal disorders 7
Higher levodopa doses (especially >6 mg/kg) are associated with greater risk of weight loss 7

Weight gain can occur in early disease stages with dopaminergic treatment or after deep brain stimulation (DBS) 3, 6
Patients undergoing DBS should be monitored as weight gain is mainly fat mass accumulating in the abdominal region, potentially increasing metabolic syndrome risk 3, 6