Nutritional status and body weight change with the progression of Parkinson’s disease. Deep brain stimulation targeting the subthalamic nucleus is a well-established method in the treatment of advanced Parkinson’s disease. Assessing its role in regulating non-motor symptoms remains a challenge. It has been observed that patients undergoing deep brain stimulation surgery may have an increased risk of significant weight gain, but studies on this subject are rather scarce. The benefits of deep brain stimulation surgery may be limited by the risk of metabolic syndrome. The change in eating habits involves, among others, increased appetite for sweets or an increased number of snacks between main meals, which is a negative phenomenon. Postoperative changes in metabolism can be explained by the effect of stimulation of the subthalamic nucleus on the hypothalamic activity, especially given their anatomical proximity and the fact that the energy balance is regulated by the hormones of the hypothalamic-pituitary axis. Considering the possible complications of the procedure, special attention should be paid to patient’s eating habits. Cooperation between dietitians and doctors is needed to control possible postoperative weight gain and to prevent metabolic disease. Nutritional intervention and promotion of new eating habits adequately adapted to patient age, the severity of symptoms, treatment method or the intensity of physical activity is the basis of a holistic approach in the treatment of Parkinson’s disease.