Taste or diet balancing?

Two groups of adult male rats were given ad lib access to a nutritionally complete diet (Purina Chow) and either a 32%-sucrose solution (w/v) or a separate container of dextrinized starch. A control group was allowed access only to Purina Chow. All groups consumed the same total caloric intake. Further, the composition of the diets selected by the two carbohydrate groups did not differ, although rats with access to sucrose gained weight at a signficantly greater rate than the starch group or the control group. These results suggest that the balance between dietary items plays an important role in the selection of food items and that the mechanism used in determining balance is not based on factors such as taste or feedback from body weight.