Association between body roundness index and constipation using data from NHANES 2005–2010

Obesity, particularly visceral fat, is a well-established risk factor for various gastrointestinal disorders, including constipation, possibly due to its metabolic and hormonal effects on bowel motility, though the mechanisms remain unclear. The Body Roundness Index (BRI), a novel and reliable anthropometric measure, has been validated as a precise indicator of visceral fat. However, its relationship with constipation remains uncertain. This population-based, cross-sectional study analyzed data from 6,898 participants in the National Health and Nutrition Examination Survey (NHANES, 2005–2010) to assess this association. Binary logistic regression analyses, adjusted for multiple covariates, revealed that higher BRI levels were significantly associated with a lower likelihood of constipation. Participants in the highest quartile had 32% lower odds of constipation than those in the lowest quartile (adjusted OR: 0.68; 95% CI: 0.54–0.86; P: 0.0013). As this was a cross-sectional study, the findings indicate an association between BRI levels and constipation rather than causality. These results suggest that BRI could be a practical and accessible marker for identifying individuals with different susceptibility to constipation, potentially aiding clinical assessment and guiding preventive strategies. © The Author(s) 2025.