Abstract: Objective: This study was conducted to evaluate the physiological effects of mung bean starch RS-3 on the obesity index and adipose cell profile of Sprague-Dawley rats. Methodology: A total of 35 male, 1 month old Sprague-Dawley rats were divided into 5 groups and given Fructose Medium Fat (FMF) feed containing Corn Starch (CS), mung bean starch (MS) or Resistant Starch (RS) for 6 weeks. In addition, the diet AIN 93G was used as the standard (STD) feed. Results: The results showed that the rats that were fed the RS diet (FMF-RS3-14 and FMF-RS3-28) had a lower feed intake and weight gain compared to those fed the fructose medium fat-corn starch (FMF-CS) or FMF-mung bean starch (FMF-MS) diets. The intervention of the FMF-CS diet led to an increase in the obesity index, whereas, the RS diet decreased the obesity index. Conclusion: The replacement of CS with RS at a dose of 28 g/1000 cal (FMF-RS3-28) for 6 weeks was effective in preventing obesity, with a Lee obesity index of 301.8.