I always eat lunch and I always go away from the computer. It’s important to get away from work for a while! Working from home is no reason not to take any breaks.
Usually I do leftovers because I try to only allow myself about 30 minutes, although if I do a chore it often stretches to 45 min. I also try to take my lunch break at around the same time each day, although obviously if I’m in the middle of something it waits.