I'm not going to advocate this, since I'm more turned on by guys with gaunt faces (defined bone structure).
Chubby cheeks = gross. Lol. Sacrifice the boy-cuteness for some man-hotness - I think most, if not all girls know what I'm talking about.
Serenity: Remember Lawrence Stiers? His face is PERFECT.
Besides, I'm no health expert but it seems like gaining weight in JUST your cheeks is almost impossible - you'll run the risk of gaining weight in your neck ... undefined jawlines are so gross.