The waist-hip ratio: a flawed index.

Area of Science:

• Anthropometry
• Public Health
• Biostatistics

Background:

• The waist-hip ratio (WHR) is widely used to predict health risks like cardiovascular disease and diabetes.
• Previous research suggests WHR may be an inappropriate metric, yet individual components (waist circumference [WC] and hip circumference [HC]) have opposing health associations.
• WC correlates positively with adverse health outcomes, while HC shows a negative correlation.

Purpose of the Study:

• To evaluate the efficacy of using waist circumference (WC) and hip circumference (HC) as separate independent variables versus their ratio in health-related regression analyses.
• To determine if separate analysis of WC and HC provides a more accurate prediction of health outcomes.
• To highlight the underappreciated role of hip circumference (HC) in health assessments.

Main Methods:

• Utilized multiple regression analyses with health-related measures as dependent variables.
• Compared the predictive power of WC and HC as separate independent variables against their combined ratio.
• Included general body size measures, such as height, in the regression models.

Main Results:

• Treating waist circumference (WC) and hip circumference (HC) as separate independent variables resulted in significantly closer fits to the data compared to using their ratio.
• This novel approach enhances the accuracy of predicting health-related measures.
• Including general body size, like height, further refines the regression models.

Conclusions:

• Waist circumference (WC) and hip circumference (HC) should be analyzed as distinct predictors rather than combined into a waist-hip ratio (WHR) for improved health outcome prediction.
• This approach offers a more nuanced understanding of body composition's impact on health.
• Further research could explore alternative anthropometric measures, like thigh circumference, to potentially replace hip circumference (HC).