Background <p>Hyperinsulinemia and insulin resistance (IR) are early indicators of metabolic dysfunction that often precede the development of Type 2 Diabetes (T2D). Identifying these conditions in apparently healthy youth—who may not yet exhibit clinical symptoms—is essential for early intervention. Therefore, we conducted this community-based study to determine the prevalence of hyperinsulinemia, IR, and their associations with measures of adiposity and body composition in 16-25-year-old adolescents and young adults in Mumbai, India.</p> Methods <p>Participants (<i>n</i> = 1313, M_age 19.6 (2.1) years, 65.2% females) reported socio-demography, medical history, and physical activity levels. Hyperinsulinemia was classified as fasting insulin ≥ 15mIU/ml and/or stimulated insulin ≥ 80 mIU/ml and IR as HOMA-IR &gt; 2.5. Anthropometry and blood pressure were measured. Sex-adjusted logistic regression analyses were performed to examine the association of adiposity measures with hyperglycemia and hyperinsulinemia. The odds ratios (ORs) and their 95% confidence intervals (CI) were calculated, significant at <i>p</i> ≤ 0.05.</p> Results <p>The prevalence of hyperinsulinemia, IR, overweight, and obesity was 39.7%, 17.3%, 15.0%, and 20.5% respectively. Of those with prediabetes (4.5%), more than half (58.1%) were overweight and almost one-third (29.1%) had abdominal obesity. The prevalence of abdominal obesity was 15.1% in participants with normal weight and 36.4% in those with overweight or obesity. Additionally, we observed that 30.1% of participants who were normal or underweight had hyperinsulinemia, and one-third of those with IR were neither overweight nor obese. The odds of hyperglycemia increased from 2.41 times in individuals with overweight (95% CI 1.91, 6.71, <i>p</i> = 0.03) to 4.67 times in those with obesity (95% CI 1.33, 6.37, <i>p</i> = 0.01). Hyperinsulinemia showed significant associations with body fat percent (OR 1.13 (95% CI 1.02, 1.29) <i>p</i> = 0.006), waist-to-height ratio (OR 1.66 (95% CI,1.15, 3.30), <i>p</i> = 0.02), and blood pressure (OR 1.08, 95% CI 1,03, 1.20, <i>p</i> = 0.04).</p> Conclusions <p>The high prevalence of hyperinsulinemia and IR in adolescents and young adults and their associations with obesity and elevated blood pressure highlight a clustering of cardiometabolic risk factors. The findings related to the prevalence of hyperinsulinemia and abdominal obesity in participants with normal weight suggest a need for comprehensive screening and further research to develop targeted interventions.</p> Clinical trial number <p>Not applicable.</p>