You could use the Realtime Updates API and look for changes for the "feed" connection. Have a look at the docs here.
https://developers.facebook.com/docs/graph-api/reference/user/
Be aware that if you receive a notification, you actively need to pull the fead data by issueing
GET /me/feed?since=LAST_UPDATE_TIMESTAMP
where LAST_UPDATE_TIMESTAMP is the timestamp when you pulled it for the last time (you should store this in your application).