To connect to Facebook, tap on the gear icon at the top left-hand side of your game screen and then tap Game Login and Log in with Facebook. You will be asked to confirm you want to connect with Facebook.
You can add friends for Food Street via the Invite button that you see in your game on the friends bar. Your friends on Facebook, who play Food Street, will become your neighbors.
The app does not post to Facebook or send friends notifications via Facebook.
Connecting with FB allows you to see your other facebook connected friends in game. This means you can request help from each other.