Background Low back pain is one of the most common types of work-related musculoskeletal disorders (WMSDs). There are no consistent results on the relationship between body mass index (BMI) and low back pain in available research.

Objective To explore the dose-response relationship between BMI and low back pain in Chinese occupational population, and to provide basis for formulating intervention measures for low back pain.

Methods A comprehensive literature search was conducted in January 2024 across the following databases: CNKI, Wanfang Data, VIP (Chinese Scientific Journals Database), SinoMed, PubMed, Web of Science, and Embase. The search period spanned from the inception of each database to December 31, 2023. Published literature on the relationship between BMI and low back pain in the Chinese occupational population was retrieved and screened usingpre-determined inclusion and exclusion criteria. The quality of cross-sectional research literature was assessed using the American Agency for Healthcare Research and Quality (AHRQ) recommended quality evaluation criteria, followed by data extraction and a dose-response meta-analysis.

Results Seventeen qualified publications were selected and covered a total of 11268 research subjects. The results of meta-analysis showed that there was a dose-response relationship between BMI and low back pain, and the combined OR value and 95%CI were 1.03 (1.02, 1.05). The Begg's funnel plot and Egger's test showed no publication bias (t=1.29, P=0.218). The subgroup analysis, meta-regression and leave-one-out sensitivity analysis showed that the results of this meta-analysis were stable. The non-linear dose-response curve showed that the risk of low back pain increased with elevated BMI with a slight increase once BMI reached 21.5 kg·m⁻².

Conclusion There is a dose-response relationship between BMI and low back pain, and weight loss intervention can reduce the risk of low back pain.