"The combination of plummeting blood sugar levels, a greater
sensation of hunger, and a memory of a meal high on the glycemic
index led to the researchers' conclusion: "This combination of
physiological events may foster food cravings with a special
preference for high [glycemic load] carbohydrates, thereby
propagating cycles of overeating."

http://www.latimes.com/news/science/...,1772900.story