If you can resist the chips, i would say quite easy.
Everywhere we went served the main (e.g. Stew, burger, chicken) and then charged extra for all the sides (chips, veg, salad). The prices were astronomical (we didn't have time to get out of the city to hunt for non-tourist traps).
So it was quite easy to just buy the protein.
But we had a great time.
Watch out for the chocolate too. Lots of shops. Lots of white, milk and dark. Buy carefully!
They really love their "moules frites" there, mussels served with chips and mayo. Depending on how strict you are with your carbs you may be able to sneak a couple of chips slathered in the mayo. Then walk it off as much as possible round the beer museum. They offer around 300 different varieties, so statiscally at least one must be low-carb.
I'm completely off chips but thanks for the info, might interest my non diabetic wife. Unfortunately won't get much time for sightseeing as I'll be there for work.