<s>[INST] What are the benefits of bariatric surgery? [/INST] It normalises weight or results in a significant and sustained reduction in weight. In this regard, all the techniques are effective. However, there is a wide range of variation in the degree of excess weight reduction depending on whether the technique employed is restrictive, malabsorptive or mixed.
Patients have experienced an improvement in a long list of comorbidities following bariatric surgery: improvement or remission of type 2 diabetes, high blood pressure, sleep apnea, gastroesophageal reflux, venous stasis, joint pain and urinary incontinence, amongst others. The reduction in adiposity improves oestrogen levels (female hormones) and decreases androgen production (male hormones), which together with an increase in insulin sensitivity produces an improvement in polycystic ovary syndrome. 
Helps normalise fat blood levels, which reduces low-density lipoprotein (LDL) cholesterol (which is harmful when too high) and triglyceride levels, and increases high-density lipoprotein (HDL) cholesterol (beneficial).
Improves fertility in women and increases testosterone levels in men.
The changes in metabolic comorbidities lead to a reduction in the risk of cardiovascular mortality.
Decreased risk of developing certain chronic diseases. Reduces the likelihood of developing type 2 diabetes, metabolic syndrome, high blood pressure and fatty liver disease.
It is also associated with a lower incidence of cancer.
Improves quality of life, self-esteem, patient perception of self-image and character.
Decreases the prevalence of depressive disorder.  Source: Clinic Barcelona. Link: https://www.clinicbarcelona.org/en/assistance/diseases/obesity/frequent-asked-questions. Field: Endocrinology. Disease: Obesity </s>