Estrogen
The No. 1 trigger of breast growth is the release of the primary female hormone, estrogen. When a girl goes through puberty (about age 12), her ovaries release more estrogen, which triggers the growth of breast tissue. From age 12 to about age 18, her ovaries will slowly release estrogen, per the genetic coding in her DNA. Furthermore, when a woman becomes pregnant, her ovaries release more estrogen to prepare the breasts to breast-feed, which stimulates the mammary glands in the breasts to grow. By proxy, the breasts grow as well (often by at least one cup size).
Genetics
Genetics are also responsible for how fat is distributed throughout a woman's body. That is, a woman's genetic makeup may have developed more fat cells in the breasts, which means that the more fat she consumes, the more she will gain weight in her breasts. In this sense, a woman who is genetically predisposed to gain weight in her breasts will gain larger breasts by eating more fat. Another woman, however, who is not genetically predisposed to gain breast weight will likely gain more weight in her thighs, stomach and hips.
Tags: about ovaries, breasts grow, gain weight, gain weight breasts, genetically predisposed, genetically predisposed gain
