Obesity has become a global health crisis in adults, and islinked to conditions like diabetes, cardiovascular diseases, and cancer. This study explored associations between body mass index (BMI) and laboratory parameters in healthy individuals to identify risk factors and guide targeted interventions in Turkey. It was found that screening and lifestyle changes can help prevent and manage obesity-related health issues. This retrospective case-control study analyzed 2153 adult participants using medical records between 2021 and 2024. The study included those with good overall health; those under 18 years of age or had organ failure, chronic metabolic disorders, obesity complications, or were on multiple obesity-related medications were excluded. Data collected included demographic details, waist-to-hip ratio (WHR), BMI, and laboratory findings. Statistical analyses, including Pearson and Spearman correlations, Mann-Whitney U testand t test, and receiver operating characteristic analysis, were performed using SPSS 24.0 (IBM Corp., Armonk, NY). The study, comprising 1016 men and 1137 women, revealed that 31.8% of adults were obese. Gender disparities were evident, with a higher prevalence of obesity observed in women: 76.5%, 68.8%, and 45.3% for classes 1, 2, and 3, respectively, compared to corresponding rates of 23.5%, 31.2%, and 54.7% in men. BMI significantly correlated with WHR. Despite the disparity between BMI and WHR between men and women, positive correlations were found between BMI and age (r=0.4) and serum uric acid (SUA) levels (r=0.5). The Mann-Whitney U test also demonstrated a significant association between BMI andfasting plasma glucose level, low-density lipoprotein(LDL), triglycerides, alanine aminotransferase (ALT), uric acid, platelet count, and lymphocyte count (all p values<0.005).Despite the poor correlation with BMI, SUAlevelsemerged as a potential obesity predictor, with a 4.1 mg/dl cutoff value, exhibiting 50% sensitivity and 34% specificity (p<0.001; area under the curve, or AUC, 0.67; 95% CI 0.65-0.70). There was no significant link between BMIandaspartate aminotransferase, hemoglobin, mean platelet volume, neutrophil and lymphocyte count, vitamin D, thyroid-stimulating hormone, and free thyroxine 4 levels. This study found significant associations between BMI and laboratory parameters, including serum uric acid, fasting glucose, LDL, triglycerides, and ALT. WHRwas also closely linked to BMI, with notable gender differences in body composition. These significant findings underscore the complex nature of obesity and highlight the importance of gender-specific considerations and biomarkers in research and management strategies that are crucial for understanding and addressing this global health crisis.