Breast Implant Sizing After Gastric Bypass - 650cc Too Big?

After massive weight loss, the elasticity of the tissue is poor. Breast implants tend to "bottom out" fast. The larger the implants, the greater the tendency to bottom out quickly. This then requres redo surgery.
My advice to most patients who have had massive weight loss is to have a breast lift (often with an extension into the armpit), and, if necessary, the smallest implant that gets the job done.
650 cc would in my opinion be much too large for somebody with your frame.

Thank you for the question and picture. Despite your good description of your body type and goals, online consultants will not be of specific enough help to you. Generally speaking, the best online advice I can give to ladies who are considering  breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully.  Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you're looking for. Ask to see lots of examples of his/her work.

2. Have a full discussion and communication regarding your desired goals  with your plastic surgeon. This communication will be critical in determining  breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as  “natural” or “C or D cup”  etc means different things to different people and therefore prove unhelpful.
 Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup  size may also be inaccurate.
 The use of computer imaging technology may also be very helpful during this communication process.

3.  Once you feel you have communicated your goals clearly,  allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals.  Again, in my practice, this decision is usually made during surgery.
I hope this (and the attached link) help.

Deflation from weight loss is common in many women. For many women the breasts are the first place where they lose and gain weight noticeably. Breast implant size is hard to determine without being integrally involved in the process. Discuss with your surgeon the sizes you are considering and see if they can supply some pictures of women in your similar situation.