Behavioral and Dietary Determinants of Body Shape Assessed by ABSI in a Mediterranean Clinical Sample

Objective A Body Shape Index (ABSI) is a validated anthropometric measure describing body shape independently of BMI and height. This study aimed to evaluate the association between ABSI and dietary quality and eating behaviors in a Mediterranean clinical population. Design We conducted a cross-sectional study analyzing associations between ABSI and diet/behavior using Pearson correlations and multivariable linear regressions adjusted for age, sex, and BMI. Setting The study took place at a Mediterranean diet-based nutrition clinic in Rome, Italy. Participants The sample included 1,640 adult patients attending follow-up visits at the clinic. ABSI z-scores were calculated and standardized by age and sex. Weekly food intake was assessed using 7-day food diaries, and behavioral preferences were collected via structured questionnaires. Results The Pearson correlation between BMI and internal zABSI was weak but statistically significant (r = 0.113, p < 0.0001), confirming that ABSI captures body shape independently from BMI. As expected, ABSI strongly correlated with waist circumference (r = 0.78, p < 0.001). Playing a sport was inversely associated with zABSI (β = -0.365, p < 0.001). Nighttime eating (β = 0.237, p = 0.001), snacking between meals (β = 0.133, p = 0.014), and preference for sweet over salty foods (β = 0.025, p = 0.010) were positively associated with higher ABSI values. Conclusions In this Mediterranean clinical sample, ABSI identified behavioral and dietary correlates of body shape-related risk. Promoting physical activity and addressing nighttime eating may help improve anthropometric profiles linked to abdominal fat distribution.