Effects of physical exercise on food intake and body weight: experimental study in tumor-bearing rats

ABSTRACT

Cancer cachexia is frequently observed in tumor-bearing patients or animals with diabetes-like syndrome. Physical exercise has been shown to reduce insulin requirements in diabetics. Objectives: To evaluate the effects of daily physical exercise on foodintake and body weight in an experimental tumor-bearing rat model (Walker 256 carcinosarcoma). Methods: Wistar adult rats were submitted to a similar daily manipulation protocol except for physical exercise (running pad continuously for 60 minutes/day), and randomly distributed as to the presence of tumor or exercise into eight groups Group 1 (Saline day 1 + No exercise for 50 days), Group 2 (Tumor day 1 + No exercise for 50 days), Group 3 (Saline day 1 + Exercise for 50 days), Group 4 (Tumor day 1 + Exercise for 50 days), Group 5 (Tumor day 1 + Exercise for 25 days + No exercise for following 25 days), Group6 (Tumor day 1 + No exercise for 25 days + Exercise for following 25 days), Group 7 (Exercise for 25 days + Tumor day 25 + Exercise for following 25 days), Group 8 (Exercise for 25 days + Saline day 25 + Exercise for following 25 days). Results: Body weight was significantly lower in Exercise (mean coefficient 1.29 ± 0.17), than in No exercise (mean coefficient 2.2 ± 0.16) - p<0.001. In the tumor-bearing rats, exercise did not affect significantly daily food intake - p=0.415. Conclusions: Daily physical exercise significantly affected body weight in this animal model, but did not have impact on food intake.