I usually hit Subway if I'm out eating alone. Just make sure to look up the calorie/fat values online so that you know which ones to choose (since not all of them are healthy). I.e. a Turkey Breast 6" wheat bread sub with cheese, and just mustard is 320c and 6.5g of fat.

[Other "safe" choices are Roast Beef, Turkey Breast and Turkey Ham, and Chicken Teriyaki]

Compare this to say McDonald's Big Mac with 540c and 29g of fat, well...I'm sure you get the picture.

Just make sure you don't ask for condiments such as mayonaise (a killer in terms of calories/fat) on your sub and you'll be safe. And of course don't spoil it by taking a non-diet soft drink with itlah.