Weight loss and all-cause mortality: A propensity score matching cohort study

Background: Weight loss was supposed to help with decreasing risk of premature mortality. However, results on this topic remain debatable and limited by study design. Objective: The present study aimed to investigate the association between weight loss and all-cause mortality among US adults with overweight or obesity in a national cohort study by using propensity score matching (PSM) analysis. Methods: A total of 5486 pairs of participants were matched in the National Health and Nutrition Examination Survey (NHANES, 2003-2015) after PSM. Hazard ratios (95% confidence intervals) (HRs (95% CIs)) were employed to evaluate the association between weight loss indicated by long-term weight loss (LTWL) and allcause mortality by using Cox proportional hazards regression models. Results: During a median follow-up of 6.8 years, 674 participants died from all-cause mortality. In each PSM match, compared with participants with LTWL < 5%, the HRs (95% CIs) for participants with LTWL of 5-9.9% (2877 pairs), 10-14.9% (1315 pairs), and >= 15% (1294 pairs) were 1.18 (0.83-1.68) (P = 0.366), 1.65 (1.17-2.34) (P = 0.005), and 1.91 (1.21-3.00) (P = 0.006), respectively. The significant increased risk of allcause mortality for LTWL >= 15% remained among male, female, participants aged >= 65 years, without weight loss intention, with non-communicable diseases, and without exceeding estimated energy requirement. Conclusion: Weight loss especially for being >= 15% should be cautious for US adults with overweight or obesity.