For me low carbs food works very well. Especially low on "fast" carbs, they are excluded for the most part. Plenty of protein and fat.
However, I do eat fast carbs during long rides - e.g Clif bars, bagels etc. After rides - high protein food for recovery.
What I found to be the most important is to not cut carbs (and calorie intake in general) too much, so that you'll start loosing weight fast. The consequences are pretty much what Carbonfiberboy describes:
drastic loss of power and high power endurance. Basically, you'll still be able to ride all day long, no problem here, but all climbing will suddenly become so much more difficult, slower and more painful; maintaining high speed will become impossible after few seconds etc. - everything that will require high intensity efforts will suffer. A lot.
PS. About the results. Reducing fast carbs intake reduces appetite, so helps to maintain food intake under control.
From 235 lb got down to 160 lb. Never felt so good in my life.