I have one thing to say, which is: Pølser, Pølser and more Pølser!! Visit Leiv Vidar.no.

The UK don't really have hot fast food at Petrol Stations, but usually the expensive packet sandwiches which you buy out of desperation, so this is something Norway has to offer above the UK.
After having been brought up and lived in the UK for 22 years I knew the food I liked, the brands and where to get them from. However when I moved to Norway, the differences in food and drink where one of the first things I had to get used to.
Brands which I was used to were gone but there were usually alternatives to what I generally liked, such as no Galaxy chocolate (or Cadburys I think) but instead the Norwegian Melkesjokolade was a great substitute.
However, what I did miss was the variety of foods and drinks I was used to. Perhaps its because of the amount of different cultures and people in the UK, providing that extra required variety.
Norway does have supermarkets such as Rimi, Coop and Rema 2000 along with the more expensive food stores, but alcohol is generally supplied from the Vinmonopolet or "drinks store".
Even things liked sliced bread is not something hugely available in Norway, where they prefer to have a loaf of bread and cut it themselves.
I was at work on one occasion and saw how Norwegians have their sandwiches. They generally don't use two pieces of bread with a filling, but instead have one piece of bread with a topping. This Norwegian open sandwich is called a brødskive. However, I would sit there eating my English sandwich and would watch them as they had to separate their sandwiches with paper, otherwise they would stick together and then had to fiddle with it and put some extra toppings on, the topping would fall off as they were eating it..... argh, it made their lunches so much more complicated!!! Just use another piece of bread!!!
Its these type of differences which I had to adapt to (although sometimes keeping my English ways were better). The food wasn't alien and some things which you liked you could no longer get but it didn't take long to find some alternative to suit you.
The UK is a fast food orientated culture, with generally every type of take away within walking distance of your home. However the fast food culture in Norway is almost nonexistent with trips for an Indian Curry or such, meaning traveling for miles to a major city to find one.
The choice for fast food in Norway is generally limited to MacDonald's and Burger King and they don't even have KFC in Norway.... NO KFC!!!. I went mad for the first few months, but got used to it by then.
I remember looking at www.kfc.co.uk, whilst in Norway and drooling, wanting to lobby the government to introduce the franchise (very sad I know), but I guess it was just something I had been brought up eating and now it wasn't available.
This could be one of the reasons why I did not see that many overweight, or obese people in Norway as their culture is about healthy eating, fresh air, clean water and outdoor living.
The only option was to live the Norwegian way, which is to be more healthy in your choices. I ate more fresh fruit and vegetables, salads and fish, however like the world over "eating healthily = expensive".
There are certain foods and drinks which are expensive in Norway, namely meat and alcohol and even the average Norwegian would rather travel to Sweden to buy them in bulk which generally saves them money.

Drinking alcohol in Norway made me appreciate it much more and slow down my drinking. Instead of binge drinking and getting drunk within a few hours in the UK, pubs and bars are open sometimes 24 hours in Norway so you spread your drinking out over a longer period.
Of course you can not live in a different country and not try everything on offer. Being adventurous is part of the experience so when a dish was mentioned as either being a delicacy or a staple Norwegian food, I was willing to give it a try.
One such delicacy is known as Lutefisk. I was told "you must try Lutefisk as it is a delicacy, its only rotting fish!" (mmm yummy). Lutefisk has the consistency of jelly, but with a fish taste and is generally served with potatoes, mashed peas and bacon. There is a good section on Wikipedia on Lutefisk for more in depth information. I cant say I was a fan of the food and to be honest I don't think anyone is, but they have it, rarely, due to "tradition".
There is a photo of me inspecting the Lutefisk before it was served up on the Gallery Page.
With Lutefisk you generally drink Aquavit, which is translated to mean the "water of life" and well, its a very heavy going spirit. So with the bland, jelly fish tasting Lutefisk and the killer Aquavit... it was an interesting meal.
On another occasion I traveled to the mountains and in the hotel restaurant they had a selection of meats. When I say a selection, it was basically one of everything that moves including Moose, Bear, Rabbit, Deer and even Kangaroo. Again, being adventurous I tried one of each (sorry to the vegetarian readers) just to say I had done that.
Fish is a staple diet of Norwegians, although I was not a fan of Fiskeboller (fish balls... I mean, balls made of fish) as they tasted a bit bland. Otherwise I tried a variety of fish dishes, including fresh prawns from the harbour, crayfish which we caught ourselves and even once I had whale meat. Norwegians are fans of fishing and I had some fishing trips to beautiful areas of Norway, although I never caught anything, being an Englishman.
One thing which I really loved about Norway is the fresh clean water they have in their homes.
Not only to bathe and shower in, but also to drink as the water tastes fantastic, almost like spring water.
The water is safe to drink and is only mildly treated, compared with the harsh English water packed full of chemicals.
To sum up, the way to adapt to Norwegian Food and Drink is to be open minded and not be afraid to try new things.
You will generally find something which is a good alternative to what you are used to, so you wont starve, but you will need to let go of the thoughts and tastes of your home country and embrace the Norwegian way.
Having meals with friends and socialising is a great part of Norwegian life and Norwegians will like to try out new things on you for the experience, so go for it, although on the odd occasion you may need to have a strong stomach.