Hi there. My family lives in Baltimore, although I'm originally from New Jersey...at any rate, I've been living in the UK for three years, having moved here to be with my partner.
I do sometimes miss Baltimore, though. What a great city. In addition to Baltimore, I lived in Brooklyn, Houston, Spokane (WA), Salt Lake City, and Philadelphia, before I finally left the US. I always liked Balto. the best. The Land of Pleasant Living, and all that. I used to live in Bolton Hill, and after that I lived in Hampden. Baltomoron tip: If you move abroad, and you like Old Bay, you'd better bring a supply yourself! Plenty of fish and shellfish to put it on, but you won't find Old Bay in the market anywhere outside the US!
There is MUCH less choice of LC convenience foods here. Oh, the Atkins shakes and bars are here, and a few other things (mostly mail-order), but the prices are shocking compared to what similar things cost in the USA. In general...although LC has certainly caught on amongst the UK populace as a effective and safe way to lose weight, the food companies and CERTAINLY the government are way behind in that regard.
If you don't rely on LC convenience foods, you will be fine here. It's very easy and tasty to base your diet on fresh meat, fish, and green vegetables. In fact, I think the beef, lamb, and poultry is far fresher and tastier here than it was in most US supermarkets. I have also been very pleased with the fish I've been able to get in the UK...I had to re-learn my fish catechism because of the vast differences between the eastern US and typical UK catches, but once I did I was able to make excellent selections, far better for the price than anything I got in the US even in coastal cities. Vegetables: There's no problem buying low carb veg in UK supermarkets, although to be perfectly honest, if you have a Hindu greengrocer's anywhere nearby (loads and loads of them here), you may well get fresher vegetables from them than you do from the supermarket.
If you move over (unless you are military, that's a whole different world because they have the PX with all manner of American products), say goodbye to the following: any form of Taco Bell; Krispy Kreme or anything like it (unless you live in/near London, in which case you can get them at Harrod's if you're willing to make the journey and pay top dollar...I live an hour out of London by subway and so far, I haven't been); Any fast-food "low carb" alternative meal, it is on the menu at Mc D's and BK in the US, but not here (I was actually laughed at when I requested a low carb option); sugar free ice cream of any kind--low carb, diabetic or whatever--unless you go to a specialty shop and, again, pay top dollar; Hidden Valley Ranch dressing in any form (BRING PACKETS YOURSELF if this is an indispensable diet ingredient for you).
But if you move anywhere near London, say hello to: Indian food that beats anything I've ever had in America, there is absolutely no comparison; A vast variety of good and reasonably cheap (compared to US prices for the same thing) French and Italian table wines; a large variety of extremely interesting cheeses, from the UK and Europe, even more wine and cheese if you go to France, which is very easy to do from the UK; delicious cream for your coffee. NB on coffee, if you are a coffee snob you may be disappointed at what you can get in the UK unless you go to a specialty shop (which I do). This is a tea-drinking nation, and they procure some of the best teas in the world. It's just not my thing. I am a coffee addict from way back.
Doritos in the UK are bizarrely sweet. I still have no idea why anyone would want that amount of sweetness in a corn chip, but that's what sells here. So although I was a Dorito addict in the States, I have not had any since coming over.
On the other hand, I have to admit that these people have figured out how to douse chips (US: steak fries) with curry sauce in such a way that it tastes like the food of the gods. I try to stay away from that.