Here are a few ingredient substitutions and recipe swap ideas for various special diets and dietary concerns.
Weight Maintenance/Management
Bulk up grain based dishes, such as pasta, rice, etc., with vegetables. Chopped broccoli for instance has a similar texture to grains like rice and bulgur wheat to a pasta dish will bulk up your meal while adding more nutrients and fiber without the added calories.
Diabetic & Hypoglycemia Friendly
Sometimes going grain free or drastically reducing the amount of grains, even whole grains, can greatly improve insulin sensitivity, for more information on this topic, check out this article
http://www.mercola.com/article/carbohydrates/lower_your_grains.htm
Beans, legumes, winter squashes, such as butternut, acorn and spaghetti, make good grain alternatives. If texture is a concern, no fear! Chopped broccoli, steamed cauliflower and quinoa (which is not technically a grain but a high in protein seed) would be perfectly acceptable options as well.
Gluten Free
Use toasted nuts in exchange for croutons in a salad.
Use Romaine lettuce leaves for wraps. If calorie content is of no concern, corn tortillas work as well.