>>94683089corn syrup is electrolyzed from corn starch into dextrose (basically glucose, a monosaccharide and the one your blood carries) which is low in sweetness and thus you need a lot to flavor food. the more common sweetener, sucrose, is somewhat sweeter than dextrose but is a disaccharide which is the bond of 1 dextrose and 1 fructose, the other common monosaccharide which is foreign to animal anatomy (mainly in fruits and agave) and is more difficult to digest, but is much sweeter.
the human body can convert unusual sugars like this but it makes absorbing them slower, which is considered to be a health benefit. however, the inverse is also true where you can use enzymes to convert dextrose into fructose in a lab, making corn syrup much sweeter allowing you to consume less sugar and have a lower blood sugar impact while doing it. the commercial form of this is high fructose corn syrup, which is good for you actually.