We identified three mediators (CRP, IL-6, and FEV1) of the associations of pneumonia with BMI and WC, given (1) the statistically significant effects of BMI and WC on pneumonia; (2) the associations of BMI and WC with the three factors; (3) the statistically significant effects of the three factors on pneumonia; and (4) the 95% CIs of mediation proportion that did not contain zero. Here, CRP is linked to pneumonia.