Maybe corn syrup isn't to blame, says UW study

Beverages containing high-fructose corn syrup — that supersweetener blamed by some for the nation's obesity crisis — actually affect people's appetites no differently than drinks made with regular table sugar, researchers at the University of Washington have found.

It's a small study — 37 subjects — but its authors say it appears to undermine a recently popular theory that high-fructose corn syrup contributes to weight gain by making people feel less full than other sweeteners do.

The study showed that "people don't seem to react differently to the different kinds of sugar," said Pablo Monsivais, nutritional-sciences research fellow at the UW and the lead author of the report, which appears in this month's American Journal of Clinical Nutrition.

Monsivais cautioned that the findings were limited to high-fructose corn syrup in beverages only, and the results may not apply to the solid form of the sweetener used in cereal, peanut butter and thousands of other food products.

And the study may do little to stem a public backlash against the cheap sweetener that has led some grocers and food manufacturers to eliminate it from shelves and assembly lines.

Researchers asked subjects to drink one of five types of beverages in the morning: two colas containing different versions of high-fructose corn syrup, sugared cola, diet cola and 1 percent milk. Then they were invited to all-you-can-eat lunch buffets more than two hours later.

People who drank the three sweetened colas in the morning said they felt equally full. At lunch, they all consumed similar numbers of calories.

A likely explanation is that once inside the body, the different sweeteners are indistinguishable, Monsivais said. The sugar in acidic beverages, such as cola, split into glucose and fructose molecules just as high-fructose corn syrup does.

But the experiment also turned up several dietary side notes worth exploring.

Subjects who drank the milk ate the smallest lunches. On the other hand, the people who had diet cola or drank nothing at all ate the biggest meals, presumably because they were hungrier.

But when researchers added up all the calories consumed from both the morning beverage and the lunch, subjects who drank diet cola or nothing consumed as many as 15 percent fewer calories than the other groups.

In short, people who had milk or the colas with sugar or syrup ate less at lunch, but not so much less that it balanced the calories they got from their morning drinks.

"The way the body adjusts for the earlier calories isn't perfect," Monsivais said. "If I gave you a 50-calorie cookie now, you wouldn't eat 50 calories less at lunch."

So Monsivais advises people who are watching their figures to drink water, preferably along with the meal, to help feel full.

"It displaces calories that you would have otherwise eaten," he said.

Kyung Song: 206-464-2423 or ksong@seattletimes.com