Facial filler or fat transfer for gaunt face? (Photo)

Fat transfer is harder control and more unpredictable in my opinion. I would use a combination of Juvederm Voluma and Teosyal RHA 4 layered over the top with a cannula to the cheek area to get a natural lift. You do have quite a bit of laxity so you could use anywhere between 3-6ml to get the result you like.

For longest lasting results I like Bellafill or Sculptra.  There are advantages and disadvantages of both of these fillers.  Although I occasionally recommend fat injections, i don't typically use it along the cheekbones.  Radiesse is an excellent mid-lasting filler for the cheekbone area.  Approximately 2 cc's on either side of the face would give you a fill similar to what you are demonstrating.  That would coincide with a little less than one "kit" of Bellafill (approximately 5000.00 for 5cc's), and around three vials of Sculptra (approximately 3300.00).  The Radiesse is considerably less expensive, but doesn't last as long.  Your best approach will be to make an appointment with a Physician that is experienced in injecting all of these fillers to discuss your options.  Good luck.