Here's the most concise quote I could quickly find on the theory of why HFCS is so bad for you:
"The theory goes like this: The body processes the fructose in high fructose corn syrup differently than it does old-fashioned cane or beet sugar, which in turn alters the way metabolic-regulating hormones function. It also forces the liver to kick more fat out into the bloodstream.
The end result is that our bodies are essentially tricked into wanting to eat more and at the same time, we are storing more fat. "
From the same article:
"One of the issues is the ease with which you can consume this stuff," says Carol Porter, director of nutrition and food services at UC San Francisco. "It's not that fructose itself is so bad, but they put it in so much food that you consume so much of it without knowing it."
Also:
"Because high fructose corn syrup mixes easily, extends shelf-life and is as much as 20 percent cheaper than other sources of sugar, large-scale food manufacturers love it. It can help prevent freezer burn, so you'll find it on the labels of many frozen foods. It helps breads brown and keeps them soft, which is why hot dog buns and even English muffins hold unexpected amounts."
All excerpts from the article here:
http://www.sfgate.com/cgi-bin/articl...DGS24VKMH1.DTL
There are a million articles out there if you Google "HFCS".
Personally, I'm in the camp that agrees that it's not so much that HFCS is evil in and of itself - it's what food manufacturers are DOING with it that's the bigger problem. They are putting this stuff in everything because it's cheap and accessible - the end result being that something like salad dressing (which, if you made your own, would likely contain little to no sugar) is stuffed to the gills with it. We're consuming it in foods that don't require it, and in quantities that were previously unheard of....that I have a problem with.