Yes, good point. There's actually a whole school of thought looking at this--a hypothesis that people eat to maintain their glycogen stores at an accustomed level, suggesting that people might eat less calories when a high carbohydrate food is also low in fat. This is usually looked at through a carbohydrate-positive lens, probably because the idea came up when the low fat craze was in full swing. But it makes as much sense to say that, even as a very low fat high carb food like a plain potato might not spark the appetite "excessively," a very low carb food might do the same--because, if appetite is geared to restoring glycogen levels, then why would a person overeat butter, or a fatty pork chop, if the carbs aren't along for the ride?