huge iOS build size even with empty scene

I have a doubt, when i took iOS build even with a empty scene, it comes around 275MB (library files causing this), when we upload in app store - will it take the same size or the size of assets we used for games. I am developing a 2D game in unity5 free edition. If it takes the same size, is there any way to reduce the size. Unity 5.0.1 XCode 6.3.1 OSX 10.10.3 Thanks in advance, Ben