To maintain a healthy weight, medical professionals emphasize that diet and exercise are key. But a new study suggests that for those who are obese, weight-loss surgery is more effective at reducing body weight, compared with non-surgical methods.

The findings, published in the BMJ, suggest that weight-loss surgery also increases remission rates of obese patients with type 2 diabetes and metabolic syndrome.

The Centers for Disease Control and Prevention (CDC) shows weight loss surgery is gaining popularity. A study from New Hampshire demonstrates that annual rate of weight loss surgery – also known as bariatric surgery – increased from 3.3 per 100,000 American adults in 1996, to 22.4 per 100,000 in 2007.

Bariatric surgery consists of three commonly used techniques:

Gastric banding involves a surgical band being fitted around the stomach, reducing the amount of food needed to make a person feel full. Gastric bypassing involves re-routing the digestive system past the stomach, while a sleeve gastrectomy involves removing a portion of the stomach.

According to the team of international researchers, bariatric surgery can be performed on those who are obese for whom conventional weight loss methods have failed.

To qualify for surgery, current guidelines recommend that a person must have a body mass index (BMI) of at least 40, or 35 if they have other serious disorders linked to obesity.

However, the researchers note that it has been unclear how effective bariatric surgery is compared with non-surgical methods.

To find out, the researchers analyzed data from 11 randomized controlled trials involving 796 obese adults with a BMI between 30 and 52.

Some individuals were allocated to bariatric surgery techniques, while others were allocated to non-surgical treatments. Non-surgical treatments included behavioral therapy, dietary changes, increasing physical activity and the use of weight-loss medication.

The patients were then followed up over a 2-year period.

Results of the analysis revealed that those who underwent bariatric surgery lost more body weight (an average of 26 kg), compared with those who followed non-surgical methods. They also demonstrated higher remission rates of type 2 diabetes and metabolic syndrome – a series of conditions that increases the risk of heart disease and diabetes.

Following bariatric surgery, patients showed greater improvements in their quality of life and showed lower medication use, compared with non-surgical patients.

Bariatric surgery appeared to improve blood lipid profile of patients, although there was no significant difference between the two groups in blood pressure.

Furthermore, patients experienced no cardiovascular events or deaths following surgery. The researchers say the most common adverse events as a result of the procedure were the development of iron-deficiency anemia and re-operations.

The researchers comment:

This meta-analysis provides comprehensive evidence that, compared with non-surgical treatment of obesity, bariatric surgery leads to greater body weight loss and higher remission rates of type 2 diabetes and metabolic syndrome.”

However, the researchers emphasize the fact that their findings are limited to 2 years follow-up and are only based on a small number of studies and patients.

They say that research beyond 2 years after bariatric surgery is warranted, particularly to monitor any adverse events, developments of cardiovascular disease and mortality rates.

Medical News Today recently reported on a study suggesting that weight-loss groups are better than a self-help approach.