A recent study (LMS Carlsson et al. NEJM 2020; 383: 1535-43) was summarized in a quick take. Essentially, obese subjects who underwent bariatric surgery survived three years longer than a control group who had not undergone surgery but lived 5 years shorter than a reference group without obesity.

The authors speculate on the reasons why the bariatric subjects continued to have a lower life expectancy than controls after surgery:

• Above-normal BMI even after surgery
• Irreversible effects of obesity-related metabolic dysfunction
• Surgical complications
• Higher risk of alcohol abuse, suicide, and trauma (including fall-related); these factors were identified in the SOS study more often than in those who had not undergone bariatric surgery

Since there have been improvements in bariatric surgery since the time of this cohort underwent surgery (1987-2001), it is possible that the average gain in life expectancy would be greater.

Here are a few screenshots: