Objective: The aim of this study was to investigate the effects of obesity and exercise on biochemical parameters and organ weights with important metabolic and endocrine functions in the body.

Materials and Methods: In the study, 40 male Sprague-Dawley rats were randomly divided into 4 groups of 10 animals in each group after they were weaned: Group I (Control), Group II (exercise), Group III (obese) and Group IV (obese+exercise). For the obesity model fat-rich diet was applied. At the end of the study, blood samples were taken from the animals for biochemical analysis, and some organs with important physiological functions in the body.

Results: Organ weights in obese groups were found to be higher when compared to other groups. Total cholesterol, triglyceride and low-density lipoprotein (LDL) levels were found higher in obese and obese+exercise groups compared to control and exercise groups. There was no significant difference between the groups at the high-density lipoprotein (HDL) level. Alanine aminotransferase (ALT) is higher in the control and exercise groups than in the obese groups. Aspartate aminotransferase (AST) was higher in the control group than in the obese + exercise group.

Conclusion: It is thought that the increase in weight due to obesity in certain metabolically important organs, affects the function of the organ in a negative way and poses a risk for many chronic diseases. Negative changes in lipid profiles seen parallel to organ weights may increase this risk. When exercised, improvement in organ weights and lipid profiles can be considered as one of the factors underlying the beneficial effects of exercise.