Please remove this post. These instructions are for a very old version of S Health and no longer work.
S Health on Samsung Galaxy S4 helps you track all your activities to control your body status. You can change the measurement units like height, weight, temp to your metric system. To change units in S Health on Galaxy S4 do as follows:
1. Open "S health" App
2. Tap the icon on the top left, and then select "Settings" to enter to the settings
3. select "Unit Settings"
4. There you can change: Height, Weight, Temperature, Week Format, Distance. common units are available to select; cm, ft, inch, Kg, pound, Celsius, Fahrenheit