We are so gullible that the makers of HFCS (High Fructose Corn Syrup) have applied to the government to change the name of HFCS to corn sugar on food labels. Changing the name has helped sales of other products in the past, like low euric acid rapeseed oil (now canola oil) and more recently, prunes (now dried plums). The FDA could take up to 2 years to approve the new name but that isn't stopping manufacturers from using the name now in advertising.
I'm not a chemist, nor an expert on what the human body knows, so I can't say for sure that "the body doesn't know the difference". BUT... I read a Rueters report about a US study which shows cancer cells know! They proliferate (multiply) on HFCS. ("Tumor cells thrive on sugar but they used the [refined] fructose to proliferate.")
I can say that when I pound a chunk of sugar cane and get a syrup, the water will evaporate and the sugar turns into sugar crystals all by itself. (I did it myself, as a kid in school!) It's nature at work. I can also say that most of the corn now grown is GMO... and highly subsidized by the government, making it much more profitable and 60% cheaper than cane sugar.
I read a Wiki article on producing high fructose corn syrup which states, "High-fructose corn syrup is produced by milling corn to produce corn starch, then processing that starch to yield corn syrup, which is almost entirely glucose, and then adding enzymes that change most of the glucose into fructose."
Americans are increasingly avoiding HFCS, and even First Lady Michele Obama has said she doesn't want her daughters eating it. Some manufacturers are starting to get the message. Sara Lee switched to sugar in 2 of it's breads, and Gatorade, Snapple and Hunt's Ketchup have very publicly switched to sugar in the past 2 years.
The debate will continue, I'm sure, as HFCS advertising dollars go to work. However, the bottom line is too much sugar of any kind not only adds pounds, but is also a key culprit (according to the American Heart Association) in diabetes, heart disease and stroke.
As for me, I have given up all added sugars, and only eating the natural sugars occurring in my fruits and vegetables.