Objectives The relationship between obesity and occupational injuries remains unclear in the literature due to limitations in study design and sample composition. To better assess the contribution of obesity to occupational injury, we used data from a nationally representative cohort, the National Longitudinal Survey of Youth 1979 (NLSY79) in 1988–2000.

Methods We hypothesized that obesity contributes to workplace injury and tested the hypothesis using logistic regression with generalized estimating equations (GEE) and random-effects logistic regression. To ensure temporal precedence of obesity, we used the obesity level in each previous wave and examined its association with injury outcome in each wave from 1988–2000. Obesity was measured as body mass index (BMI) based on self-reported height and weight.

Results The GEE analysis showed that obesity was associated with 25% higher odds of workplace injury [odds ratio (OR) 1.25, 95% confidence interval (95% CI) 1.12–1.39; P<0.001). The random-effects regression indicated that obese workers were associated with 29% higher odds of sustaining injuries than those of normal weight (OR 1.29, 95% CI 1.15–1.45; P<0.001).

Conclusions Obesity may predispose workers to work-related injury; further research is needed to elucidate the mechanisms.

Key terms BMI; body mass index; longitudinal; National Longitudinal Survey of Youth; NLSY; non-fatal occupational injury; obesity; occupational injury; overweight; work-related injury