Epidemiological association between metabolic health obesity phenotype and chronic low back pain: a cross-sectional analysis based on the NHANES database

• Metabolically unhealthy obesity significantly increases chronic low back pain risk (OR=1.44-1.57), while metabolically healthy obesity shows no significant association. • Smoking and arthritis amplify the risk of chronic low back pain in metabolically healthy obese individuals. • BMI ≥39.73 kg/m² and waist circumference ≥125 cm are risk thresholds for chronic low back pain in metabolically unhealthy individuals. • Metabolic health status is a key factor in obesity-related chronic low back pain, suggesting targeted interventions for metabolically unhealthy obesity.