Women often attribute their weight gain to the hormone replacement.
The ovariectomized rat rapidly gains weight for three to four weeks following ovariectomy. Estrogen replacement prevented the weight gain associated with ovariectomy. Ovariectomized rats that were given estrogen, but also had access to chocolate as a diet choice, gained almost as much weight as the ovariectomized rats not given estrogen. These results demonstrated that inclusion of too much of poor diet choices in the diet can undermine the protective effects of estrogen against weight gain. These results support a later human survey that blamed diet and other lifestyle components rather than estrogen for increased body weight gain with hormone replacement therapy after menopause.