I think the idea is that foods with a low glycemic load suppress the appetite relative to high glycemic foods because they don't produce quick spikes in blood sugar and insulin production.

Ludwig's research indicated that calories being equal those given low glycemic meals ate less at the next meal and requested fewer snacks than a group on a high glycemic diet.

Other researchers are wondering if you could add more carbs as long as they are slowly digested, i.e., high fiber.

One reason I'm interested in a glycemic load diet is because it's hard to get enough fiber on the Atkin's diet, for example. I think 30 grams of fiber per day is a reasonable sweet spot given what I've read about digestive tract health, particularly the colon. In his latest revision, Atkins himself pays much more attention to fiber than ever before. And carbs are the primary source of fiber. That's the dilemma that the glycemic load concept might unravel.