Corn syrup may not boost appetite, food intake

NEW YORK (Reuters Health) - Though some have blamed the U.S. obesity problem on the corn syrup ubiquitous in processed foods, a new study casts some doubt on this idea.

Researchers found that high-fructose corn syrup did not differ from regular table sugar in its effects on people's appetite and food intake later in the day. They say the findings counter the argument that high-fructose corn syrup is contributing to the rise of obesity and type 2 diabetes.

Over the past 35 years, food manufacturers have been steadily replacing sucrose (sugar) with high-fructose corn syrup as their sweetener of choice. Some experts have argued that high-fructose corn syrup encourages overeating because of its short-term effects in the body. Glucose triggers an increase in the hormone insulin, which helps the body know that it's full; fructose, however, has a weaker effect on insulin.

Studies also suggest that fructose has a weaker effect on "appetite hormones" that help control food intake.

To further study the question, Tina Akhavan and G. Harvey Anderson from the University of Toronto in Canada conducted two tests with 31 young healthy men.

In each, the men were given various sugar solutions to drink -- containing either table sugar, high-fructose corn syrup or other combinations of glucose and fructose. All of the solutions had the same number of calories.

An hour-and-a-half later, the men were allowed to eat all the pizza they wanted.

In general, the researchers found, there was no difference in the men's reported hunger levels or food intake whether they had high-fructose corn syrup or table sugar earlier in the day.

In addition, although sugar solutions with a higher ratio of glucose to fructose raised insulin levels to a greater degree, all of the solutions suppressed the appetite-stimulating hormone ghrelin to a similar extent.

"These studies," Akhavan and Anderson conclude, "do not support the hypothesis that the replacement of sucrose with high-fructose corn syrup as a caloric sweetener has contributed to overeating and obesity because of differences in their short-term physiologic (effects)."

SOURCE: American Journal of Clinical Nutrition, November 2007.