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.