Go to your phone "Settings" > Data Sense > toggle "Restrict Background Data" on. This will basically prevent any background usage of mobile data, so if you're not connected to Wi-Fi all your apps that rely on the internet will not work in the background, i.e. your live tiles won't be updated automatically, chats won't be received automatically, emails won't be updated automatically. However, when you launch those apps, you should be able to receive whatever Internet-based information it was scheduled to received while the restriction is active.
In other words, the toggle will only restrict "background" data for apps, but it will not restrict data when the app is in use.
You may want to consult this
article and this
How-to page for more details.
