Reducing Breast Size

Does anyone know how to resuce breast size naturally? 
By:
-excercises
-diet (I'm vegan; thinking about raw veganism)
-anything else that you've tried????
My breasts are a D (maybe bigger) and I HATE how large they are. If I lost some weigt, though; would they reduce their size? I feel lile they'd also sag. :/ Idk.