DALLAS (Reuters) - People who eat two or more servings of red meat a day are much more likely to develop conditions leading to heart disease and diabetes, US researchers reported on Tuesday.

Eating two or more servings of meat a day increases the risk of suffering from a cluster of risk factors known as metabolic syndrome by 25 percent compared to those who had only two servings of meat a week, the researchers reported in the journal Circulation.

The symptoms of metabolic syndrome include excessive fat around the waist, high cholesterol, high blood sugar and high blood pressure.

The study also found that diet soda consumption was linked to these elevated risk factors for heart disease and diabetes, echoing the findings of a study published in July.

"When we found that diet soda promoted risk we were surprised," said Dr. Lyn Steffen, an associate professor of epidemiology at the University of Minnesota.

"It may be associated with compensating for eating higher calorie food. People may say, 'I can eat this cookie because I am drinking this diet soda.'"

Lots of meat, fried foods and diet soda add up to heart disease, the researchers said, and the conclusions add to a swelling body of evidence linking fast food with unhealthy lifestyles.