Background

Bariatric surgery is indicated in people with a body mass index (BMI) ≥ 40 kg/m2 or a BMI ≥ 35 kg/m2 with at least one comorbidity. The procedures can be restrictive (e.g., sleeve gastrectomy), malabsorptive (e.g., biliopancreatic diversion with duodenal switch), or mixed (e.g., Roux-en-Y gastric bypass). Bariatric surgery has multiple health benefits but also some negative outcomes. This review provides an update on the health consequences of bariatric surgery.

Methods

A systematic search of literature was conducted using the search terms morbid obesity, comorbidities, bariatric surgery, health benefits, and adverse effects.

Results

Bariatric surgery induces significant and sustained weight loss and significantly reduces the comorbidities of obesity (e.g., type 2 diabetes, hypertension, and dyslipidemia). Roux-en-Y gastric bypass appears to have better efficacy compared to most other procedures. Bariatric surgery promotes improvement of richness, composition, and functionality of gut microbiome, independently of weight loss, and this can further enhance the weight loss. Also, bariatric surgery significantly reduces the incidence of new-onset type 2 diabetes, hypertension, and dyslipidemia. The mortality rate of bariatric surgery is less than 1%. Adverse effects include procedure-related complications and malabsorption associated with hormonal disturbances responsible for mineral and vitamin deficiencies (e.g., low iron and vitamin D), hypoglycemia, and osteoporosis with fracture risk.

Conclusions

Bariatric surgery is the most effective method for obtaining sustainable weight loss and reducing the obesity-related comorbidities in people with morbid obesity. It also lowers the incidence of new comorbidities. The nutritional deficiencies caused by bariatric surgery require adequate therapy and monitoring.