Background: Non-nutritive sweeteners (NNSs) are becoming more popular as sugar substitutes for diabetic patients. Stevia is a naturally-occurring NNS that has been reported to have a number of health benefits in both humans and experimental animals. We aimed to assess the impact of stevia supplementation on food intake and weight gain as well as liver tissue histopathology in obese and non-obese rats. Also, we aimed to examine the association between stevia supplementation and sperm quality in obesity. Methods: In this experimental study, forty adult male albino rats which were divided into four groups (n=10 each). Both control and obese groups received oral supplementations of stevioside (25 mg/kg daily) as positive groups and the other obese and control groups received oral supplementations of sucrose 5 g/kg daily as negative group. The amount of food intake, weight of rats and biochemical tests were measured at baseline and at the end of the study (8 weeks), as well as liver tissue histopathology examination was done at end of the study. Results: our study revealed that there were higher levels of total cholesterol, triglycerides, LDL cholesterol, in obese group compared to control group. However, stevia supplementation for 8 weeks to obese group had non-significant changes of these parameters compared to sucrose supplementations. Regarding semen quality, there were non-significant difference between stevioside and sucrose received obese group. Nevertheless, in obese group there were decreased in sperm count and viability compared to control group. Regarding histopathological features of the liver, after induction of obesity there was increase weight of liver as well as severe damage to liver parenchyma such as cellular swelling with degenerative changes, vacuolar changes and foci of hemorrhages compared to the normal control. However stevioside supplementations for 8 weeks led to decrease liver weight and improve its histopathological features. Conclusion: stevia supplementation for 8 weeks to obese rats increased body fat %, epididymal fat pad mass, food intake (g/rat/day) and weight of rats (gm) as well as decreased liver weight and fluid intake. However, stevia supplementation had non- significant changes of rat sperm quality compared to sucrose received obese group, on the other hand, histopathological features of the liver significantly improved after stevia supplementation.
