Weight loss and malnutrition among advanced PD patients might be explained by lower food intake, mediated by fewer mouthfuls per meal and more severe tremor symptoms. Our results indicate that interventions to reduce tremor symptoms and to prompt advanced PD patients to take more mouthfuls have the potential to be clinically useful in protecting against unintentional weight loss and malnutrition. Additional data collection might facilitate the creation of early, eating-based, behavioral tests for the evaluation of the disease’s trajectory.