The NUTRISS experiment is aimed to monitor the subject crew energy balance during his long-term spaceflight, measuring mass and body composition.
The   body composition is known through a Bio-Impedance Analysis (BIA) which consists in measuring the body’s resistance and reactance. Measurements are performed with a bio-impedance analyzer. 
The experiment goals can be summarized as follow:
1.Defining programs to implement timely nutritional suggestions during the long-term spaceflights, based on body composition values
2.The time course of in-flight musculoskeletal changes will allow an evaluation of the effectiveness of such feedback
3.Optimization of astronauts’ performance and quality of life
4.Speed-up and improvement of the astronaut re-conditioning phase.
To reach the above goals, the NUTRISS experiment foresees 7 measurements sessions (Body Mass + BIA) covering all the Parmitano’s mission duration. A monthly ESA Nutritional Assessment (ENA) session will allow the Principal Investigator to evaluate the need of dietary modifications. To achieve the experiment objectives, a COTS bio-impedance analyzer, called NUTRILAB and manufactured by AKERN, will be modified and space certified by Kayser Italia. The Principal Investigator (PI) is Prof. Gianni Biolo of the University of Trieste. The Payload Developer (PD) is Kayser Italia S.r.l.The BIA measurement will be performed by using the modified NUTRILAB bio-impedance analyser, connected to four electrodes by means of its data cable. Two electrodes will be placed on the right hand of the crew member and the other two on his right foot. The Resistance and Reactance values will be provided as BIA results on the device’s display and communicated to Ground by means of an iPad App