Since both my wife and myself follow a Low Carb WOE there is no "not allowed" food in our refrigerator. If you were to look inside on any given day you would find:

eggs
hard cheese (Swiss and cheddar mostly, but also blue and colby)
lettuce (iceberg.romaine and leaf - we use vinegar and oil)
asparagus
broccoli
brussel sprouts
ground sirloin
sliced roast beef from the deli
pot roast (often left over from the night before)
chicken
bacon (we don't eat as much bacon as we use to - it seemed to
stall us)
butter
heavy cream (for use on sugar free jello)
real mayo
fish (lots of it if I have been fishing)
LOTS OF COLD WATER
Dan