Around 500kcals sounds about right. I wouldn't really call a single QP a big meal.
I think your comparison to other subs is off thought. Depending on the meat of the sub you might be reducing protein, but the Norwegian sandwich definitely has less fat (less cheese, less calories in the butter than mayo or other sauce, less fatty meats). Usually the bread preferred also has more whole grain and fibers than what's used in the US.
> the Norwegian sandwich definitely has less fat (less cheese, less calories in the butter than mayo or other sauce, less fatty meats)
Butter is much higher in saturated fat and calories than mayo, and you're putting butter on 3 slices whereas you usually only but mayo on one (per the article). One tablespoon of butter is 100 calories and 7 grams of saturated fat, one tablespoon of mayo has 60 calories and 1.5 grams of saturated fat.
If I look at the nutritional information for Kalles Kavier (which someone suggested as a topping), it seems to also be pretty high in calories with a lot coming from extra carbs (sugar).
Having eaten both the quantities really are that different. A typical American sub has much more sauce than a Norwegian sandwich has butter. Kalle's is so flavorful that you don't need a lot of it, but I agree it would be the most unhealthy choice of the ones listed.
I think your comparison to other subs is off thought. Depending on the meat of the sub you might be reducing protein, but the Norwegian sandwich definitely has less fat (less cheese, less calories in the butter than mayo or other sauce, less fatty meats). Usually the bread preferred also has more whole grain and fibers than what's used in the US.