Abstract

The present work analyses the possible influence of the colon in weight gain of obese animals. Subtotal colectomy was performed in rats fed with standard chow or high-fat diets. The results, suggested that subtotal colectomy did not exert any effect on the % of weight gain in rats administered a high-fat diet during the whole experiment as compared to controls. Animals submitted to a high-fat diet during the pre-surgery period and to a standard diet during the post-surgery period gained a lesser % of weight gain as compared to control or high-fat fed rats, together with a decrease in this parameter in colectomized animals. These changes did not agree with average food intake in rats fed with standard or high-fat diets. Surprisingly, the increase in body weight of sham-operated or subtotal colectomized rats fed with highfat diet cannot be explained by a diminished food intake when compared to controls. Moreover, the change in food intake after surgery showed a correlation with body weight in sham-operated animals, although this correlation disappeared in colectomized rats. Mortality only appeared in colectomized rats administered a high-fat diet. However, stool was normalized and presented normal characteristics when animals returned to be fed with their respective diet after surgery. The results of this study support the concept that the maintenance of a high fat diet may originate a decrease of the intake, overall in subtotal colectomized rats, possibly through neuroendocrine mechanisms related to gut hormones or to adaptive mechanism along the gastrointestinal tract.