Common table sugar is NOT the monosaccharide glucose, but
sucrose, a disaccharide of glucose AND fructose. From the linked article:
In mammals, sucrose is readily digested in the stomach into its component sugars, by acidic hydrolysis. This step is performed by a glycoside hydrolase, which catalyzes the hydrolysis of sucrose to the monosaccharides glucose and fructose. Glucose and fructose are rapidly absorbed into the bloodstream in the small intestine.
In other words, common table sugar provides both glucose AND fructose in equal quantity, so their opposing effects on appetite most likely cancel each other out, at best. Furthermore,
high fructose corn syrup, or HFCS, isn't necessarily any worse, because it actually contains glucose as well! From THAT linked article:
The most widely used types of high-fructose corn syrup are: HFCS 55 (mostly used in soft drinks), approximately 55% fructose and 45% glucose; and HFCS 42 (used in many foods and baked goods), approximately 42% fructose and 58% glucose. HFCS-90, approximately 90% fructose and 10% glucose, is used in small quantities for specialty applications, but primarily is used to blend with HFCS 42 to make HFCS 55.
If you read closely, you'll see that the most common HFCS contains glucose and fructose in very similar quantities. One form has more fructose, another more glucose, and the one that's almost entirely fructose is only used in converting the others. In fact, the most significant difference between table sugar and HFCS is, your body breaks down the sugar into what HFCS gives you straight!
I would recommend reading both of the Wikipedia articles, which mention a variety of studies on the subject. The article on sucrose notes problems caused by rapid elevation of GLUCOSE levels. It would seem there are no innocents in this debate.