Zan P, et al. - Through a retrospective single-institution study that involved 202 Chinese patients who received simultaneously bilateral total knee arthroplasty (TKA, a successful, safe, and cost-effective procedure for reducing pain and restoring function in patients with end-stage knee osteoarthritis), staged bilateral TKA, or unilateral TKA from 2008 to 2015, the researchers intended to compare 2-year body mass index (BMI) changes and to ascertain the predictors of weight change and whether clinically meaningful weight changes influenced outcomes. Post-TKA surgery, weight loss was observed in 66.8% of patients. However, only 20.7% of individuals underwent clinically meaningful weight loss. Paired t test revealed that a 2-year BMI was markedly lesser than preoperative BMI. Weight loss was markedly varied among the surgical strategy. Preoperative BMI and age were observed as predictive of clinically meaningful weight loss or gain. Also, postoperative weight loss was correlated with better Western Ontario and McMaster Universities Osteoarthritis Index and 36-item short form health survey scores. Hence, subjects faced weight loss post-TKA. Clinically significant weight change was predicted by age and preoperative BMI. Furthermore, simultaneous bilateral TKA was correlated with a greater likelihood of weight loss. Moreover, clinically significant weight loss encountered better patient-reported outcomes.