Boston (ECN) - Researchers have found that gastric bypass surgery is not effective for diabetes.

Researchers from the University of California, San Francisco carried out the study on 310 patients with an average BMI of 52 when it began.

Gastric bypass surgery is used to shrink the stomach of patients to suppress their hunger, and spark weight loss.

Those who were not diabetics were able to lose 60% of their excess body weight after a year went by.

Patients who were diabetics though had trouble losing weight, due to their insulin medicine, and other drugs.

Drugs taken by diabetics help promote the production of fat and high cholesterol.

The study was published in the journal Archives of Surgery.