Apps taking more space than they should?

So I have an iPhone with 16gb of data (only comes with 12.8 as the things that come with the iPhone take up space) and I've noticed that most of my apps are taking up way to much space than they should. I only really use social media, for facebook it should only take up around 50mb but it uses around 500mb. Another example vine takes up 400mb when it should only use 10mb, and twitter takes up a full GB but should only use 18mb. Why is my phone doing this? And how can I change it?

Download iFunBox on your computer and then remove the apps cache.
Unfortunately there's no way to do it from your iPhone.

Cache files add up over time. Facebook is one of those apps that does that. That's normal. Short of getting an app like Phone Clean (for computers) to clear the cache ever so often.