Syncing all the Health & Fitness data into a one source

So I've decided to try out this whole quantified self thing with a bunch of apps and devices and my goal is to collect data on my walking & running, gym exercise, diet, and weight (using a Withings scale). Now there are a lot of great Apps and services and apps that do those things, and many of them work well together also.

Now is there any App/service out there that can collect this data/import it from external sources and display it in a clear manner and utilise that data one way or the other? I'm very new to this whole thing so I'd appreciate your points of view and how you're doing this stuff, if you're doing it at all.

So far I'm using the Withings WS-50 which plays well with many services, I plan to use an app that utilises the m7 coprocessor of the iPhone 5s to track my walking/jogging, so I won't be needing another gadget with me, and then for Gym and diet I guess the only option is to manually input this stuff into an app. As mentioned I would prefer to get all this data into one place for easy analysis. Any input is appreciated. Thanks!