https://wccftech.com/samsung-galaxy-watch-4-could-get-a-body-composition-monitor/

Smartwatches are only getting better and better as time goes; new smartwatches can measure stress, skin temperature, and heart health as well. A new tip suggests that Samsung might add a new sensor to the Galaxy Watch 4 that is expected to launch in August later this year. According to Max Weinbach, Samsung might be adding a bioelectrical impedance analysis (BIA) sensor on the Galaxy Watch 4. For those wondering, this sensor is found on smart scales, as well.

For those wondering, BIA is a method to measure the composition or the percentage of fat to muscle and other tissues of the human body. The sensor reads the impedance or disruption of a low voltage current that is sent through the body. BIA then uses this data to estimate whether the wearer is too lean or obese as bone, muscle, fat, and other tissues have different electrical resistance qualities.