By Philip Brasher
Des Moines Register

WASHINGTON - A corn product used to sweeten soft drinks, breakfast cereals and sandwich bread may be contributing to America's obesity problem, some scientists say.

Use of the sweetener, known as high-fructose corn syrup, has skyrocketed since its introduction in the 1970s, coinciding with a sharp rise in obesity. Now, research suggests that the fructose found in the corn syrup and other sweeteners is more readily converted into fat than other sugars.

"When you go back and look at it, there are significant differences between how (high-fructose corn syrup) is handled and traditional sugars are handled," said Louis Aronne, an obesity specialist at the Cornell University medical school. "It deserves a further look to understand this, because it could have a big impact on the health of people."

Officials in the food and beverage industries say there isn't enough research to support the concerns about fructose, which consumes 6 percent of the nation's corn production. They argue that obesity problems are more due to lack of exercise than eating too much.

"I'm more concerned with what the total caloric intake of an individual is against what their activity level is and do the two match," said Alison Kretser, a registered dietitian who is director of scientific and nutrition policy for the Grocery Manufacturers of America. "If you're an individual with excess weight, then you need to make small changes, increasing the amount of walking you do a day and eating smaller portions."

Americans are consuming a lot more sugary foods and beverages than they used to or should be, according to the government.

The average daily American diet contained the equivalent of more than 31 teaspoons of sugar in 2000, the amount found in nearly four cans of soda, according to the U.S. Department of Agriculture. That is nearly three times as much sugar as the government recommends and is a 22 percent increase during the last two decades. The figures do not include sugars that are found naturally in fruits and vegetables.

About a third of the fructose people consume is from fruits, vegetables and other natural sources. The other two-thirds comes from sweeteners that are added to drinks and foods.

In 2000, an average American consumed 62.7 pounds of corn syrup, compared with 65.6 pounds of cane or beet sugar.

Japanese scientists developed a process to convert cornstarch into high-fructose corn syrup in the 1960s. The syrup is less expensive than beet or cane sugar and has become the sweetener of choice in sodas and fruit drinks. It's also found in many breakfast cereals, cookies, breads, frozen treats and jelly.

Unlike glucose, a major component in table sugar, fructose doesn't trigger responses in hormones such as insulin that regulate energy use and appetite.

That means fructose is more likely to be converted into fat than glucose, scientists say. More research is needed to determine the long-term impact of fructose on body weight, said Peter Havel, a scientist at the University of California-Davis.

Jeanette Jordan, a spokeswoman for the American Dietetic Association, said the important thing is not to eat excessively.

"There's nothing wrong with using (high-fructose corn syrup) as long as the food that it's used in is taken with moderation," she said.