Three rodent diets were custom manufactured by Harlan Laboratories (Madison, WI). The composition of each diet is described in our previous report [11 (link)]. In brief, the base/control diet was prepared from Teklad Global 16% Protein Rodent Diet (Harlan Laboratories), which was ground and repelleted. This diet has a fixed formula and is nutritionally balanced, containing 16% protein and 3.6% fat that support the growth and maintenance of rodents and not containing alfalfa or soybean meal, thus minimizing the levels of natural phytoestrogens. The phyto-β-SERM diet was prepared by adding equal parts of genistein, daidzein, and equol (LC Laboratories, Woburn, MA) to the base diet. The soy extract diet was prepared by adding a commercial soy extract product, Healthy Women Soy Extract Supplement (Amazon, Seattle, WA), to the base diet. The phyto-β-SERM and soy extract diets were designed to deliver to a mouse a daily intake of 0.25 mg of added total phytoestrogens, or 10 mg/kg (body weight [BW]) mouse per day, assuming a 25-g mouse eating 2.5-g diet per day. This mouse dose is biologically equivalent to a daily intake of 50mg in humans. The conversion of human dose to mouse equivalent dose was based on the conversion factor of equivalent surface area dose from human to mouse [13 (link)]: 50 mg/60 kg (BW, human) × 12 (human to mouse conversion factor) = 10 mg/kg (BW, mouse). This human dose is the estimated average amount of phytoestrogens that Asians regularly ingest from the dietary consumption of soy foods [6 (link)] and is the recommended daily serving dose for many commercial soy extract supplements sold to the women in the United States, including the one tested in this study [14 (link)].