You might find information from other fitness apps that you have on your phone when you open Google Fit. You can check which apps share data with Fit and disconnect any apps you don't want.
Disconnect Google Fit from the Health app
- On your iPhone, open the Health app.
- At the top, go to your profile.
- Under "Privacy," tap Apps Google Fit.
- To control access to a specific data type, in the "Allow Google Fit to read data" list, turn on or off each type.
- To stop access to all data, at the top, tap Turn all categories off.