Cant say it much better than djansen said it. Diet = the food you eat, not programs for dropping un-wanted pounds
Doctors are trained in medicine not nutrition. I wouldnt take any advice from a doctor about nutrition to heart. Also I wouldnt take all nutritional advice from nutritionist either, but that is just me. If you go see a nutritionist, quiz them. See if they really know what they are talking about, or just feeding you crap.
On the bright side, you can drop fat from anywhere on your body, but you cant target specific areas. Women generally load fat in their butt and boobs first, and it is usually the last place that weight drops off. Diet is 70% of being healthy, excersise is the other 30%. Once you find what works for you, your body will progress to the ideal size and frame it needs/wants to be.
Good luck!