Soy has many anti-nutrients and is a hormonal disrupter. Contrary to popular belief soy was not consumed in great quantity in traditional Asian diets.

Perhaps the best survey of what types/quantities of soy eaten in Asia comes from data from a validated, semi quantitative food frequency questionnaire that surveyed 1242 men and 3596 women who participated in an annual health check-up program in Takayama City, Japan.  This survey identified that the soy products consumed were tofu (plain, fried, deep-fried, or dried), miso, fermented soybeans, soymilk, and boiled soybeans. The estimated amount of soy protein consumed from these sources was 8.00 ± 4.95 g/day for men and 6.88 ± 4.06 g/day for women (Nagata C, Takatsuka N, Kurisu Y, Shimizu H; J Nutr 1998, 128:209-13).