Fructose is processed differently in the body than the far more common sugar, glucose. Glucose causes the pancreas to release insulin which drives sugar from the bloodstream into cells. Glucose causes fat cells to release leptin that makes you feel full so you eat less; it also prevents the stomach from releasing ghrelin that makes you hungry. On the other hand, fructose does not cause fat cells to release leptin and does not suppress ghrelin. This means that fructose increases hunger to make you eat more. Furthermore, the liver converts fructose far more readily to a fat called triglyceride, than it does with glucose. High triglyceride levels raise blood levels of the bad LDL cholesterol and lower blood levels of the good HDL cholesterol, which increases heart attack risk.
Large amounts of fructose appear to cause insulin resistance, impair glucose tolerance, produce high levels of insulin, raise triglycerides, and cause high blood pressure in animals. Not all of these studies have been replicated in humans, but there is every reason to believe that large amounts of fructose will have the same adverse effects. High-fructose corn syrup is found in almost all non-diet soft drinks and fruit beverages, and in a wide variety of processed foods. However, high-fructose corn syrup is no more significant as a dietary source of fructose than ordinary table sugar. It is only high in fructose compared to ordinary corn syrup.
Several recent studies show that drinking large amounts of soft drinks is associated with increased risk for obesity and that the extra gain in weight is not due just to the calories in the soft drinks. Calories consumed in beverages do not fill you up the way calories in solid foods do. High fructose corn syrup is the leading sweetener in the United States today, with 4.5 billion dollars worth sold each year. High-fructose corn syrup first appeared in the American market in 1966, and now the average American takes in 62.6 pounds per year. Check the list of ingredients in the foods you buy.