Lead author Adam Reppert, a clinical dietitian at Swedish Covenant Hospital in Chicago, said metabolic syndrome is a cluster of symptoms including large abdominal girth, high blood pressure, high cholesterol levels and insulin insensitivity -- that together signal a significantly higher risk for heart disease and type 2 diabetes.

In a telephone survey in 2005, 5,077 Illinois adults provided information about chronic health conditions, exercise habits and their intake of fruit, vegetables and other sources of calcium.

"We found that metabolic syndrome was more prevalent in the older, less affluent population, in people with less education and in those who engaged in less physical activity, consumed calcium-rich foods less frequently and had hypertension and hypercholesterolemia," Reppert said in a statement.

The study, published in the American Journal of Health Promotion, found about 16 percent had metabolic syndrome -- lower than national estimates of 23.7 percent to 34.5 percent.

The study found that adults who reported little or no daily exercise had nearly twice the risk of developing the condition and that adults who failed to consume calcium-rich foods regularly had about 1.5 times the risk of developing metabolic syndrome, compared to adults who ate calcium-rich diets.