Congratulations you lost weight since you cut carbs out of your diet, and please let me apologize for using the evil word, carbs. Well I hate to burst your bubble, but that weight you just lost is water weight and the full name of the dietary component that you eliminated is carbohydrate and not just carbs. So instead thinking carbs are unnecessary lets take a good look as to why we need and are required to eat the wonderful macronutrient.
We are all told to do cardio to strengthen our heart and aerobic exercise to strengthen our lungs. Is the goal for cardio/aerobic exercise to strengthen these organs? Is that even possible? Is their function, or lack thereof, the reason we breathe so hard? Should I just keep asking you questions?