The relationship between intimate partner violence and body mass index based on a Chinese national survey

The objective of this study was to explore the association between intimate partner violence (IPV) and body mass index (BMI), and to further investigate how the severity and specific subtypes of IPV are associated with BMI outcomes.

A national, cross-sectional survey was conducted.

Data from 23,469 adults in the 2023 Psychology and Behavior Investigation of Chinese Residents were analyzed to examine associations between IPV and BMI. IPV severity and subtypes were assessed via a validated five-item scale, and BMI was categorized according to Chinese standards. Multinomial logistic regression and restricted cubic spline models evaluated both linear and nonlinear relationships, with subgroup analyses exploring variations by sociodemographic and psychosocial factors.

Among 23,469 participants, IPV exposure showed a significant inverted U-shaped relationship with BMI, peaking at a score of 7.41; mild to moderate IPV exposure was associated with a higher risk of overweight/obesity, while severe IPV was associated with underweight. Subtype analyses revealed that sexual violence and controlling behaviours were correlated with underweight, whereas emotional and verbal abuse were associated with overweight and obesity.

The study demonstrated that the severity and subtype of intimate partner violence (IPV) exposure have distinct effects on body mass index (BMI) outcomes, underscoring the need for integrating IPV screening into weight-related assessments and for developing targeted, context-specific public health interventions.