I used to make Zucchetti Which is grated Zucchini and I'd quickly saute and use that as my pasta it was awesome. Riced cauliflower is also a great substitute for rice. Breads are hard to replace but if you can choose to have a salad instead with more protein (like tuna, egg, ham, chorizo etc) you will find you don't miss the bread at all. Goodluck!