You may try to make your own low carb version http://www.diabeticgoodbaking.com/2013/04/ivealways-thought-that-it-is-not.html or buy one https://www.ocado.com/webshop/product/LivLife-Low-Carbs-Seriously-Seeded-Loaf/96565011?dnr=y
I personally just switch to different foods for lunch: salads...