I don't think Fat Secret natively syncs with any devices. Many here use a 3rd party app called Fitmess (see fitmess.herokuapp.com/) to link their Fitbit data to Fat Secret. The Fitmess FAQ indicates it's for syncing Fitbit to FS but it also indicates "FitMess is a platform that allows you to exchange your data between different fitness or calorie tracking apps that might or might not support one another. " You may want to check Fitmess out and see if you can get it to work with Google Fit.