Estradiol increases consumption of a chocolate cake mix in female rats.

Female Sprague-Dawley rats were given an opportunity to eat chocolate cake mix (CCM) using a common brand of cake mix, while standard laboratory food was also available. They took large amounts of the CCM, often taking more than 20 g in 24 h. Some animals were given a single injection of 1 of 6 doses of estradiol valerate (ranging from 0.09 to 10.0 mg/kg) and others were given vehicle. Estradiol valerate provides for sustained release of estradiol. Those receiving estradiol ate more than those receiving vehicle at doses larger than 0.09 mg/kg. Further, with a dose of 10 mg/kg, greater intake among estradiol-treated females was apparent 2 months post-injection. Methodological issues of neophobia and conditioned avoidance were addressed in the study's design and may explain why increased intakes were observed here in contrast to the consensus that estradiol reduces food intake.

Estradiol valerate and intake of sweetened water.

Recently, it has been shown that female rats receiving very large doses (e.g., 2 mg) of estradiol valerate (EV) take considerably more alcoholic beverage than placebo controls. The question asked, with these procedures, is whether the enhanced appetite for alcoholic beverages was specific to those beverages or was a reflection of a general increase in appetite. Female rats were provided with various sweetened beverages. In one experiment, they were provided a palatable saccharin solution (0.25% solution) and a less palatable one (2% saccharin solution). EV treatment led to more intake of the palatable saccharin solution and reduced intake of the less palatable solution. EV induces changes leading to enhanced appetite for some ingesta (including palatable saccharin solutions and alcoholic beverages), but surely not all ingesta.