Why is FCPX importing files larger than they natively are?

Hey all. I'm not going to overcomplicate my questions with specs and stuff: I have a project, and I'm importing 20GB of footage, but for some reason, my project file is almost 200GB. I cannot figure out for the life of me how or why Final Cut Pro is turning 20GB of raw files into a 200GB project file. Any recommendations...?

Thanks in advance