This is not "breaking news" because I read it some months ago but I totally forgot commenting about. It is anyhow something that has become part of my daily routine when in the supermarket: checking that whatever sweets I may buy do not have glucose syrup, which is the official term by which high-fructose corn syrup is marketed officially over here (EU normative, I presume), in spite of having more fructose than glucose.
From Science Daily (where you can read more details):
"When rats are drinking high-fructose corn syrup at levels well below those in soda pop, they're becoming obese -- every single one, across the board. Even when rats are fed a high-fat diet, you don't see this; they don't all gain extra weight."
High fructose corn syrup is widespread in industrial foods, from sodas to cookies and nearly everything sweet because it is cheap (thanks to US subsidies to maize production), is sweeter than regular sugar (sucrose) and is easier to mix because of its liquid state. However there are still some brands that just use normal sugar.
Academic reference: Miriam E. Bocarsly et al., High-fructose corn syrup causes characteristics of obesity in rats: Increased body weight, body fat and triglyceride levels. Pharmacology, Biochemistry and Behavior, 2010. Pay per view.