I brown bag it, because I'm frugal. My office is just a few blocks from a wonderful public market with gluten free and organic food, but I can't afford to eat there every day. I wish I could.
Here are some things I pack for lunch. If you are trying to cut carbs, these will help you since they are all gluten free. I avoid using gluten free replacements. They are expensive and quite frankly, most of them don't taste very good. There are some good ones, but it takes a lot of trial and error, or the recommendation of friends, to find them. So most of my lunches are naturally gluten free.
I found these great lunch containers at Wal-Mart. They were $4 each for a set of two and come with the fork, and knife in the rectangular containers. The salad containers have a separate cup for the dressing, so you can make salads up ahead of time. These containers allow me to make lunch at one time instead of every day.
Salads - I buy the bagged lettuce and spinach and mix them together. You can add whatever vegetables you want. For protein I use chicken breast, tuna, salmon, whatever I happen to have on hand.
Quesadillas - Corn tortillas, cheese and your choice of other ingredients. Chicken, beef, spinach, beans, whatever you want.
Portabella mushrooms - Flip a mushroom cap upside down. Top with spinach, marinara sauce, sliced tomato and mozzarella or provolone cheese. Bake at 350 until the cheese is lightly brown.
Veggie lasagna - I made this veggie lasagna last week. It makes a 9x13 pan and I'm the only one who will eat it, so I cut it into single serving pieces and froze it. I can just take out a single serving and put it in my lunch container.
Breakfast - Eggs are good protein. Scrambled with some veggies and you're good to go.
Egg salad is a good option. Mix in a half of an avocado for extra protein. Spread it on sandwich bread, put it in a lettuce wrap, or eat it plain. Here I added some cottage cheese and I'll grab a pear for my fiber filled fruit.
Last week I experimented with a recipe. I made a spaghetti squash. (If you want to save time, pierce the squash a bunch of times, then microwave it for about 15 minutes. ) I mixed the squash with some parmesan cheese, a wedge of Laughing Cow cheese and some canned salmon.
Wraps - Just because you're gluten free doesn't mean you can't do wraps. Use corn tortillas or lettuce instead of bread.
Get creative with your meals.