OBJECTIVE: An increasing population in many countries consume diets high in fat and refined sugars (often in carbonated soda). Although high-fat diets have been extensively studied, less attention has been paid to carbonated soda. The aim of this study was to investigate the combined effects of a high-fat diet and soda consumption on oxidative stress and inflammation in Wistar rats. METHODS: Thirty-two male and female Wistar rats were equally divided into four dietary groups as follows: control, soda only, high fat (HFD), and high fat and carbonated soda (HFD/soda) and were placed on the dietary treatment for 14 wk, after acclimatization. At the end of the dietary treatment period, anthropometrics, lipid profile, lipid peroxidation, antioxidant activity, and inflammatory markers were assessed. RESULTS: Anthropometric variables and lipid peroxidation were increased in animals fed the high fat and soda diet. There was a decrease in antioxidant levels. CONCLUSION: The results from this study demonstrated that a HFD in combination with soda increased the effects of oxidative stress and inflammation in Wistar rats.