The question of how large a role heredity plays in health is a vital one,
since if health is determined primarily by genetics, then there isn't much point in improving an environment factor like nutrition. While it may be convenient to blame everything on one’s heredity, I believe it's role is overstated, especially in relation to modern diseases like cancer, diabetes, heart disease and obesity.
It's not unusual for a nation to have very low rates of degenerative diseases, until they start shifting their natural diets toward western style depleted foods. When they do, their rates of heart disease, cancer, diabetes, and obesity all rise rapidly and dramatically, often within just 15 to 30 years.
In utero and on birthing,
a baby's gut is still developing and very immature. In utero the baby is nourished through the umbilicum, with breast milk being the continuum of this nourishing process on birthing. Breast milk is the bridge between the inside and outside world. Breast milk houses natural human nutrients for the immature gut and body systems to continue to develop outside the womb.