Bariatric surgery is significant health benefits in addition to weight loss, including improvement in cardiovascular risk factors, fatty liver disease, diabetes management, and reduction in mortality. Being overweight or obese are both rising medical problems. There are many detrimental health effects of obesity. These include heart disease, diabetes mellitus, many types of cancer, asthma, obstructive sleep apnea, and chronic musculoskeletal problems. There is also a focus on the correlation between obesity and mortality. Overweight and obese people, including children, may find it difficult to lose weight on their own It is common for dieters to have tried fad diets only to find that they gain weight, or return to their original weight, after ceasing the diet.

Some improvement in patient psychological health is noted after bariatric surgery 51% of bariatric surgery candidates report a history of mental illness, specifically depression, as well as being prescribed at least one psychotropic medication at the time of their surgery candidacy.

Weight loss surgery generally results in greater weight loss than conventional treatment, and leads to improvements in quality of life and obesity related diseases such as hypertension and diabetes mellitus . The Lancet in 2021 found that bariatric surgery was associated with 59% and 30% reduction in all-cause mortality among obese adults with or without type 2 diabetes respectively.