Background: The most important clinical disorders in patients with Parkinson disease (PD) are akinesia which seriously deprive patients from motor skills. The implantation of subthalamic stimulation electrodes is an interesting therapeutical option to reduce these symptoms. PD patients have a frequent and significant weight gain after surgery. A first study highlighted energy expenditure (EE) alterations confirmed in a recent study, both based on our 2 calorimetric chambers (CC). We used jointly data from CC and from wearable device like Actiheart (AH). AH records heart rate and physical activity, and calculates EE from these parameters added with gender, age and weight. The objective was to compare the EE results obtained by the 2 measurement systems (CC and AH). Methods: The total duration of the measurements was 24 hours during the exact same observation periods for simultaneous recording data from the CC and from the AH. The periods included 1) sleep for sleeping metabolic rate (SMR) during the quietest 197.55 (± 62.07) consecutive minutes of the night, 2) the quiet period of wakefulness excluding activity and meals. For this quiet awake period, we compared the EE from CC and AH when the patients were in 2 distinct states: EE in patients with medications and no blockade (EEon), and EE in patients off medications with akinesia (EEoff). 19 PD patients were observed before surgery, and 11 of them after surgery. Results: Both measurement methods (CC and AH) showed an increase in SMR after surgery (6.80% ± 12.88%, P=0.036 and 4.17% ± 4.24%, P=0.001, respectively). After surgery, weight gain (5.14% ± 6.21%, P=0.004) led to an increase in the BMR (3.12% ± 3.45%, P=0.002) calculated with Schofield equations which are used by AH for the calculation of the EE when the patients were inactive. For the EEon and EEoff periods, the CC made it possible to highlight an EEoff greater than the EEon at equal posture of the volunteers (7.89% ± 10.85%, P=0.002), whereas the AH did not detect any modification (1.61 ± 9.93, P=NS). Conclusion: If AH make it possible to perform estimates of EE on an outpatient basis at home, there are situations for which CC represent an indispensable tool. This is the case to obtain a real value of SMR or to highlight a difference in metabolism with patients having different states of motor disorders (ON vs OFF) and no change in physical activity.