Effect of DHEA on macronutrient selection by Zucker rats.

Zucker rats are a frequently used model in obesity research. Dehydroepiandrosterone (DHEA) reduces their rate of weight gain and caloric consumption. So far, most studies have been conducted while the animals consume laboratory rodent chow, which is low in fat. In the experiments of this communication, Zucker rats were offered fat as a food choice. The goal was to determine how the consumption of fat would affect their weight gain and what effect DHEA would have on macronutrient selection. It was found that Zucker rats both male and female, lean and obese selected nearly 40% of their calories as fat when allowed to choose from nearly pure carbohydrate, protein, and fat foodstuffs. Consuming these three macronutrient diets they ate more calories and gained more weight than chow-fed controls over short periods of time. DHEA administered as an intraperitoneal injection decreased caloric intake of Zuckers. This decrement was quantitatively most important on fat intake. DHEA also prevented weight gain. It is concluded that the availability of fat food affects weight gain in Zucker rats and that DHEA modifies the selection of food such that Zucker rats eat less fat.