I had a fat transfer to my breast 5 weeks ago. What can I do to enhance/improve results? Will gaining a little weight help?

It can take several  months for you to see the final result once the swelling subsides. If you put on weight, you may see an increase in breast size.

It takes at least 3 months to see the final results from breast fat grafting.  At 5 weeks you probably have some residual swelling. The fat cells are metabolically active, so you will see minor changes with weight gain and loss.  But, at this point I doubt there is a benefit in transient weight gain. 

The success of fat transfer is highly technically dependent, and many factors contribute to this.  The fat that is being transferred is a living graft, and as such the cells must survive in order to see lasting results.  Things like how the surgeon harvests the fat, how it is handled and prepared in the operating room, and how it is injected will all have a significant bearing on the success of the procedure and the final results.  Even in the best of circumstances we expect a measurable loss in the fat volume transferred, sometimes even as high as 30 - 40 %, and for this reason fat transfer as a primary method of augmenting the breasts should only be expected to produce modest results at best.  This means maybe a cup size in increased volume, or more likely just a fuller version of the same cup size already being worn.  If a patient wants more volume than that, it is best to perform standard breast augmentation with implants.  The transferred fat is living, functioning fat tissue, and as such it will respond to gains and losses in weight.  We should see stability in the volume of the transferred fat by around 2 - 3 months postop, and thus at this stage the volume that you have is likely the volume that you will see long term.  Certainly if you gain weight those fat cells may enlarge, and this may enlarge your breasts, but it will also likely enlarge other areas of your body as well such as your tummy and waistline, your thighs, and your bra line, and increases in those areas may offset any improvement in the appearance of the breasts, and make you unhappy.  It is really hard to get preferential increases in breast volume with overall weight gain - the girl (or the doctor!) that comes up with the secret to doing that will become an instant billionaire!  My advice is not to gain weight simply to increase your bustline; if you want fuller breasts than you have been able to achieve with fat transfer alone once the point of stability is reached at a couple of months postop, I would do  what most women do and undergo implant augmentation.  With the additional volume of the fat grafts to camouflage the implants, you can only hope to have more natural results than you would have otherwise.  Good luck.