Well, it’s a step in that direction, but with only 34 participants it’s possible that one or two outliers could have a large impact. I don’t know if there were any.
Although they say there wasn’t any real significant difference, they did have what appears to be a difference between the two at the 6 month mark. If other studies found that, and this one seemed to lean that way, I’d be suspicious about the results.
I can certainly see how eating 30% below maintenance for a period of time would simply force you to metabolize fat stores, over time, whether you ate sugar or not.
Heh, finally, I don’t know if fat people can be trusted to cheat on their diets within their particular dietary guidelines… at least with respect to the low GI group! I could imagine non-compliance being skewed.