Association between lifestyle profile and body composition indices (BMI, A Body Shape Index, Body Roundness

Lifestyle behaviours influence overall and central adiposity, yet conventional measures such as BMI may not fully capture lifestyle-related variations in body shape, necessitating evaluation of waist-based indices. To determine the relationship between body composition indices (including BMI, ABSI, BRI, Conicity Index) and lifestyle among adults. A hospital-based analytical cross-sectional study was conducted among 100 adults, recording demographics, standardized anthropometry (height, weight, waist circumference) and calculating BMI, ABSI (with z-scores), BRI and Conicity Index. Lifestyle was assessed using the validated FANTASTIC Lifestyle Questionnaire, and associations were analysed using correlation, ANOVA and multiple linear regression (SPSS v27). Among 100 adults (mean age 31.74±11.03 years; 48% male), mean height and weight were 168.66±9.15 cm and 71.61±15.03 kg, with waist circumference 85.54±11.35 cm and BMI 25.10±4.72 kg/m². Mean ABSI, conicity index and BRI were 0.08±0.01, 1.38±0.39 and 3.54±1.51, respectively, and the mean lifestyle score was 59.92±6.67. Lifestyle score correlated negatively with BMI (r=−0.31, p=0.002), ABSI (r=−0.38, p<0.001), conicity index (r=−0.29, p=0.004) and BRI (r=−0.33, p=0.001). ABSI and BRI decreased significantly across lifestyle categories (ABSI p=0.001; BRI p=0.009), whereas BMI and conicity index did not. Regression was significant (adjusted R²=0.21; F=12.84), with ABSI and BRI independent predictors (p<0.05). Healthier lifestyle profiles were significantly associated with more favourable body composition, with ABSI and BRI emerging as the most consistent independent indicators of lifestyle-related central adiposity beyond BMI.