London, and I think UK in general, is easy to navigate if you are on a restricted diet. With that said, I don’t know how it works if you have celiac desease, but I take it it wouldn’t be that difficult. At least most food in the grocery-stores are marked.
Obviously, as long as you speak English, there will be no language-barriers when explaining your needs. However, this time, I took the chance not to explain and just ordered what I thought would be low FODMAP (no wheat, no garlic, no onion, no lactose).
For breakfast I bought eggs and ham at the grocery-store. I cooked the eggs in my egg-boiler (sounds strange to bring an egg-boiler, but I can assure you, it has been a life saver more than once) and an extra one for lunch, just in case.
For lunch you can either go to a pub, eat sushi or find wheat-free pre-packed food at the grocery-store. There are several options for sushi in London, Wasabi being one of my favorite. Not because they have exeptional nice sushi, but because it is convenient that you can pick what you want and that each sushi-bite has been pre-packed. I wouldn’t opt for Wasabi if I was going out for dinner though, but for take-away it’s great. Many of the coffe-shops like Pret A Manger and Eat also sell pre-packed sushi-meals.
Marks & Spencer, Tesco and Saintbury’s have pre-packed meat and chicken in smaller bites, refridgerated and pre-packed. A plain salad with low FODMAP-vegetables (lettuce, tomatoe, carrot…) is also for sale at most grocery-stores and together with some meat or chicken it will make a nice meal.
For dinner your safest option is to order meat or fish with fries or rice. In London you can get a steak on every corner/pub, and I found it extremely easy to not walk around hungry. In fact, I didn’t eat much of the food I brought from home!
This was my first time going to UK after I started the low FODMAP-diet and even I have been there 2-3 times a year the last 10 years, and haveing lived in Liverpool for a year, I was surprised how easy I found it to get a full meal all day long.