Wally suggested a 1 to 1 mix of carb and fiber...

What you describe would cut carbs by half as fiber is not digestible.  Thus it would be far less glycemic than refined carbohydrates.

Be advised, however, that most fibers produce high levels of acrylamides when heated past 140 degrees farenheit.
Acrylamides are the crunchy component of complex carbohydrates formed from starches.
They are the reason that grains were the first substance found to cause cancer in 1843 ( mathematically, 120 years more obvious a carcinogen than tobacco ).  Stanislov Tanchou ( U of Paris Medical School) discovered this link when he compared per capital grain consumption with epidemiological cancer rates ( data first gathered during the Napoleonic Conquests).

Ray Audette ( a shameless Frenchman)