Although fat often has a bad reputation, you need some fat for normal hormone function and to maintain your core temperature. (healthyeating.sfgate.com)
In modern times, an increase in chemical production has led to widespread environmental chemical contamination that can affect normal hormone function in those exposed, particularly in vulnerable populations, such as children and pregnant women. (sciencedaily.com)
Soy and alfalfa are commonly included in feeds for many herbivorous animals under human care, however these diets have high levels of phytoestrogens that disrupt normal hormone functions in some species. (sciencedaily.com)