But really we are talking about two different things: GI and satiety. Yes potatoes are high GI. It would follow that they will spike your blood sugar. No claims have been made to the contrary.
Satiety is about how full you will feel per calorie eaten of that food. Multiple factors contribute to satiety. Specifically boiled potatoes score super high on the satiety index.
Not mashed potatoes. Not french fries, potatoes gratin, etc.
The topic is only tangentially related to GI.
Don't mean to be cranky here but I was hoping people would talk about the article, the underlying concept (satiety), and the research, instead of going off on lengthy discussions about quasi-related personal anecdotes.