It is a carbohydrate so will release some energy and some people eat protein only and manage.
its not nutritionally sound to restrict yourself to limited food groups, you need a good balance overall; the key is to choose your carbs wisely, you dont need to give them up altogether, just choose the more nutritionally balanced ones..ie brown rice, wholegrains etc, your body needs balanced nutrition and you need carbs for energy and metabolism!!
as long as you put out more than you put in and eat a balanced diet you will be fine and the weight will come off!!