In adults who have been diagnosed with prediabetes, lifestyle changes can delay or prevent the development of full-blown Type 2 diabetes. Results from the Diabetes Prevention Program, a study conducted by HHS and involving more than 3,000 participants, showed that a 5% to 7% weight loss lowered the incidence of Type 2 diabetes by 58%. The weight loss was achieved through dieting (cutting fat and calories) as well as exercising moderately (most participants chose walking) for at least 150 minutes a week. Use of the oral diabetes drug metformin (brand name Glucophage and others) also helped to delay the onset of diabetes in some study participants; however, it was not as effective as diet and exercise. A more recent study, called the DREAM study, showed that use of the drug rosiglitazone (Avandia) also reduced the risk of developing Type 2 diabetes in people at risk. However, drug use as a treatment for prediabetes is not recommended at this time.
Efforts to prevent Type 1 diabetes in humans have so far been largely unsuccessful, but numerous studies, many of them part of a group of studies called Type 1 Diabetes TrialNet, continue to work toward that end.