A potato is basically sugar, as far as digestion is concerned.
The "complex carb" and glycemic index thing is pretty well nonsense. A carb is a carb. The only question is whether you have a properly functioning metabolism and insulin sensitivity. They call a screwed up insulin sensitivity "metabolic syndrome". If you've developed one, typically through many years of poor eating, you need to cut out starch, because your fat cells and pancreas can't handle it properly. If you're thin, well then the glycemic index thing is useless. Your pancreas and fat cells work fine.
A carb is a not a carb. Sucrose is composed of equal parts glucose and fructose, while starch is pure glucose. Fructose and glucose are two different 'carbs' and handled much differently by the body.
The "complex carb" and glycemic index thing is pretty well nonsense. A carb is a carb. The only question is whether you have a properly functioning metabolism and insulin sensitivity. They call a screwed up insulin sensitivity "metabolic syndrome". If you've developed one, typically through many years of poor eating, you need to cut out starch, because your fat cells and pancreas can't handle it properly. If you're thin, well then the glycemic index thing is useless. Your pancreas and fat cells work fine.