Carbohydrates often get clumped together in two extreme categories: good and bad. However, carbs alone aren't bad. Everyone needs them because carbs are the body's primary source of energy. The three types of carbs -- sugar, starch and fiber -- all have a place in your diet.Even sugar is a good carb as long as the type of food from which you obtain it is healthy.owever, carbs alone aren't bad. Everyone needs them because carbs are the body's primary source of energy. The three types of carbs -- sugar, starch and fiber -- all have a place in your diet. Even sugar is a good carb as long as the type of food from which you obtain it is healthy.