Participants in the intensive lifestyle intervention portion of the Diabetes Prevention Program, which involved cutting fat and calories with the goal of reducing by weight by 7 percent, reduced their likelihood of developing diabetes by 58 percent over a 3-year period, report Dr. Richard F. Hamman at the program's coordinating center at George Washington University in Rockville, Maryland and colleagues.

At the beginning of the study all of the participants were overweight and had an impaired ability to process glucose, putting them at high risk of developing diabetes.

Another goal of the intervention was to get participants to exercise moderately for at least 2.5 hours weekly, the researchers add in their report published in the September issue of Diabetes Care.

Hamman and his team looked for factors that were the most important in reducing diabetes risk -- weight loss, exercise or dietary fat reduction. Participants' cut their fat intake to less than 25 percent of their total calories, and reduced the amount of total calories if their weight-loss goals were not met by fat reduction alone.

Weight loss was the most important factor in preventing diabetes, while cutting fat and exercising helped participants lose weight, and exercise helped them keep the weight off, the researchers found.

"Interventions to reduce the risk of diabetes should aim at weight loss as the primary determinant of success," the researchers conclude.

SOURCE: Diabetes Care, September 2006.