High fructose corn syrup (HFCS) is a main ingredient in many foods. Cheap to produce, it is also easy to store and full of calories. Nutritionists say the prevalence of high fructose corn syrup in foods today plays a major role in encouraging obesity.

Metabolic Changes

Some health experts say that the body processes the fructose in high fructose corn syrup differently than other sugars, changing one's metabolism and forcing the liver to add fat to the blood stream.

Genetically Modified

Two of the enzymes used in the production of high fructose corn syrup, alpha-amylase and glucose-isomerase, are genetically modified to make them more stable, causing concerns for people wishing to avoid genetically-modified food.

Lack of Leptin

Fructose does not stimulate insulin production, which means that leptin, a hormone that creates feelings of fullness, is not produced, meaning the brain still produces hunger signals even when full.

Hidden Calories

Because of the amount of high fructose corn syrup, some foods contain hidden or excess calories that a consumer may not be aware of.

No Healthier Than Other Sugars

Because HCFS is promoted as a "natural" sweetener, some consumers may be misled into thinking that it is more healthy than other sugars. It is a processed and refined sugar, and not made from fruit, although the word "fructose" may cause some consumers to think it does.

Source:

The Double Danger of High Fructose Corn Syrup

Is fructose dangerous?

More Information:

High Fructose Corn Syrup and Diabetes