If you want the jist of this lecture, around 1:15:00 is a good place to start, he rants about Gatorade and McD's. Otherwise, it's O-Chem(?) up to that point. Very interesting stuff. Less Fructose, more Fiber. Less Frankenburgers, more Fruits.
Leptin and ghrelin are the hormones produced in the pancreas and stomach that signal to your brain that you should start or stop eating. Some of the byproducts of fructose metabolism in the liver first cause the production of ghrelin, which stimulates hunger, and then inhibits the production leptin, which prevents the signals that you should stop eating from reaching your brain. The result is that you feel artificially hungrier and then you don't stop eating after you're full.
Eating lots of fiber with fructose should theoretically counteract this cycle to some extent, by regulating the hormones and preventing overeating.
Almost everywhere fructose is found naturally, it is coupled with huge amounts of fiber. Because of this, humans haven't really been harmed by the negative effects of fructose until very recently. The speaker in the video suggests that you can kind of mitigate the negative effects of fructose by eating lots and lots of fiber, but I don't think this has been scientifically studied yet. It makes sense theoretically, though.
Fiber also does a whole lot of other great things for you, too, and he discusses some of them in the video.
