RALEIGH, N.C. -- A new study finds more evidence of a link between obesity and a corn product used to sweeten soft drinks and some foods.

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Researchers said records show an increase in the use of high-fructose corn sweeteners in the late 1970s and '80s coincided with what they call an "epidemic of obesity."

But the researchers cautioned the figures don't provide a definite link. They examined consumption records from the Agriculture Department and combined them with previous research and their own analyses.

The study is published in the April issue of the American Journal of Clinical Nutrition.

A dietitian for the Grocery Manufacturers of America said it's not about the high-fructose corn sweeteners. She said it's about "how many calories we're eating and how many calories we're burning."

The Corn Refiners Association also refutes the study's findings.

"No single food ingredient, including high fructose corn syrup, is the culprit behind the nation's obesity epidemic. Increased caloric intake and lack of physical activity are to blame," the organization said in a statement. "This story is nothing new -- in fact, there is no story."