I have known of people who did LC eating convenience foods. Did they eat nuggets and fries with a big milkshake? No. They'd order a double burger, ditch the bun, a side salad with plenty of full fat dressing to go with it, and since it's all about the carbs, order either a diet drink or water to drink.

Five Guys will serve your bunless burger in a "bowl", and they have several LC toppings in their list of free toppings, so have as many of those on it as you like.

If you can't handle prepping on a day off work (and reheating for meals throughout the week), there's still plenty of food that requires no prep - the aforementioned rotisserie chicken, can of tuna, pre-made salads, individual serving veggies - there's even frozen cauliflower rice and mashed cauliflower available these days. So simple - no prep, just nuke and eat.

Is this ideal? Will a purist LCer eat like this? Probably not, unless they're in a time bind or away from home and kitchen, and just need something to eat when there are no other choices available. But it's still LC to eat this way - it doesn't need to be perfect and purist, just LC.