Does reducing the rate or efficiency of digestion reduce food intake?

Two strains of rats (Charles River CD and Lewis) were fed high-moisture (71% water) diets containing 50-300 mg acarbose/kg dry diet for 1-3 wk. Acarbose impaired carbohydrate digestion in both strains, as evidenced by increased fecal excretion and increased intestinal contents. For both strains the highest dose of acarbose tended to stimulate food intake, whereas an intermediate dose (100 mg/kg) inhibited food intake. The lowest dose (50 mg/kg) had no significant effect. In general the food intake-promoting effect of acarbose was more pronounced in CD rats, whereas the food intake-inhibiting effect of acarbose was more pronounced in Lewis rats. To determine whether increased intestinal bulk, due to undigested food, was responsible for the reduced food intake, another experiment was conducted in which Lewis rats were fed diets containing 5-25% cellulose. Although this level of cellulose should have increased fecal bulk to the same degree as acarbose, cellulose increased rather than decreased food intake. It is proposed that the presence of incompletely digested food in the digestive tract can inhibit food intake for several days. Because manipulating diet moisture altered energy intake without altering percentage of food excreted as feces, it is proposed that acarbose and diet moisture alter food intake by different mechanisms.