I've mentioned Dr. Robert Lustig on this blog before because he has a very popular Youtube video on the dangers of sugar in the diet. His basic take is that it's toxic.
His Youtube hit is about an hour long and some people might struggle to watch it all. Luckily, the CBS show 60 Minutes recently aired a more easily digestible piece on the debate called "Is Sugar Toxic?". Worth watching and only 15 minutes. The sugar "industry" spokesman does not have many good arguments when offered a platform at the end of the piece.
A big problem (like salt) is how many foods have sugar in them now, even foods that one would not immediately take as "sweet". It's hard to know what's in food sometimes, and impossible if the labelling is vague.