[Dynsei]

There's Herbs shown to scientifically influence healthy breast tissue plus anti-DHT's such as pygeum, red reishi, and aromatases such as white peony. There's also massage that increases prolactin, I think this is best done during menstruation or during swelling. You're right, it sounds like stress and not nutrition. People emphasize water, but juices are good as well.

Biology of the breast is important because it gives a hint into tubular breasts. Then take a look at Breast Size in Relation to Endogenus... which is the same as the reference "endogenus" which is indexed in pubmed.