Influence of increasing concentrations of ethanol on food and water intake, body weight, and wheel-running of male Sprague-Dawley rats.

Male Sprague-Dawley rats were used to study the influence of increasing concentrations of ethanol on wheel-running, food and water intake and body weight. Animals were housed individually in screen-bottom cages (n = 12) or in activity wheel cages (n = 12). Half the animals in each activity condition received an ethanol-free liquid diet, and the remainder received liquid diet in which the concentration of ethanol was increased by 5% of energy intake per week to a maximum of 35%, at the expense of dextrin. Ethanol did not significantly affect total wheel-running, but was associated with decreased total food intake when it represented greater than or equal to 20% of energy (p less than 0.001). The decreased intake was restricted to the dark cycle, while light cycle intake was unaffected. Neither water intake nor body weight (with food intake as a covariate) were affected by ethanol. In contrast, wheel-running was associated with increased water intake and decreased body weight, but did not affect food intake. No interactions between activity and ethanol were detected. It is concluded that ethanol in the concentrations tested does not affect wheel-running in male rats, but does reduce food intake and may disrupt circadian food intake patterns.