People in danger of developing type 2 diabetes often have high levels of insulin; because they are "insulin resistant," glucose is not processed properly and the pancreas compensates by producing more insulin.

Now, a study in the medical journal Diabetes Care suggests that dietary fiber might prevent so-called hyperinsulinemia -- and perhaps help ward off full-blown diabetes.

Dr. Thomas M. S. Wolever, of the University of Toronto, Canada, and colleagues compared the effect of high-fiber cereal versus low-fiber cereal on glucose and insulin in 77 non-diabetic men, of whom 35 had normal fasting insulin levels while 42 had high levels.

Those with hyperinsulinemia were significantly heavier and had large waist circumferences than the normal-insulin group. Hyperinsulinemic men also had lower HDL ("good") cholesterol and a trend toward higher triglyceride levels.