The finding came from a new study conducted by researchers at UT Southwestern Medical Center and was published in the journal Diabetes Care.
Dr. Ildiko Lingvay, assistant professor of internal medicine and first author of the research, said:
"For years, the question has been whether it is the bariatric surgery or a change in diet that causes the diabetes to improve so rapidly after surgery. We found that the reduction of patients' caloric intake following bariatric surgery is what leads to the major improvements in diabetes, not the surgery itself."
Ten patients were involved in the report and were followed in a controlled, inpatient setting during two separate times.
At first, the participants were treated only with the standard diet that patients who receive bariatric surgery are required to follow. The experts measured blood glucose levels to determine the impact of the diet.
After many months passed, the subjects received the Roux-en-Y gastric bypass bariatric surgery and followed the same diet. Once again, the scientists observed the patients' blood glucose levels.
During each of these observations, which lasted for 10 days, the volunteers consumed less than 2,000 calories total each day - the customary diet for gastric bypass surgery patients.
Results showed that during the diet-only period, fasting blood glucose levels reduced 21% on average, and after combining the diet with the procedure, levels decreased 12%.
After a standard meal, patients' overall blood glucose levels dropped 15% in the diet-only period and 18% after combining diet with surgery.
This indicates that the very strict diet given to patients after bariatric surgery is accountable for the quick diabetes remission, which usually occurs within days of the operation, the authors said. Previous research found that 67% of bariatric surgery patients were in complete remission for type 2 diabetes after 12 months.
Dr. Lingvay explained:
"Unfortunately, such a restrictive diet is nearly impossible to adhere to long-term in the absence of bariatric surgery. We found that the success of bariatric surgery is mediated through its ability to control food intake, which in turn has a beneficial effect on diabetes."
Type 2 diabetes often develops as an outcome of obesity and occurs because the body cannot meet the increased need of insulin brought upon by obesity and insulin resistance. According to a report from March of this year, people at high risk of developing type 2 diabetes can reduce the risk by sitting less and moving around more frequently.
Over 20 million people in the U.S. are affected by type 2 diabetes, according to the American Diabetes Association.
A recent study found a key mechanism in the immune system that plays a part in the development of obesity-linked type 2 diabetes. The findings, which were published in Cell Metabolism, are a stepping stone for new treatment methods, according to the authors.
If diabetes is left untreated, the disease can lead to other conditions, such as: