Get an hour for lunch.  Usually bring in a sandwich and fruit from home which 9 times out of 10 I'll eat at my desk.  There is a rest area to use if you want and kitchen facilities, can heat up items in microwave, use kettle etc.  Sometimes I treat myself to a freshly made salad box from local sandwich van.  Only go out if I have a definite reason as I'm in a remote location and you have to drive 10+ minutes to get anywhere.