There are three types
of carbs.(fiber, starch, and
sugar) All carbs are four calories
per gram, but
sugar holds no nutritional value, so if you consume a lot of sugar you may meet your caloric(energy) needs, but your body is still starving for nutrients and as a result you consume more and add the calorie surplus to your reserves. (fat) So, in my opinion, if you're trying to use your reserves, it's important that you try and avoid high sugar intake, but the other carbs are fine.