Background: Insulin resistance is one among the major factors for the cause of type 2 diabetes or its antecedent impaired glucose tolerance. According to traditional thinking, the major cause of IR is increasing BMI, which ultimately leads to comorbidities like dyslipidemia, micro and macrovascular complications. Rising BMI or waist circumference are clearly linked to insulin resistance and risk for T2DM, a number of adipose derived factors have attracted interest with respect to determining insulin resistance. Materials and methods: The study was both retrospective and prospective which was conducted at Believers church medical college hospital, Thiruvalla, Kerala, India. This study was approved by the Institutional Ethical Committee and patient consent was also taken. The study was conducted in 72 subjects for a duration of 2 years (July 2017 to October 2019). Result: The study revealed the relation between the BMI and IR in ethnic population. The results obtained were contradictory to the traditional fact that an increase in BMI is related to the increase in IR. According to our results there is no relation between the BMI and IR (r=-0.025, p=0.833). Conclusion: Hence concluded that BMI and IR are not correlated. The increase in the BMI is not the reason for the IR. The increase in the visceral fat may be the factor for IR. According to our study, we also conclude that insulin secretion and β cell mass (%) are correlated with IR. We could identify that insulin secretion is inverse correlated to the IR whereas a positive correlation between the β cell mass (%) and IR.