Answer:
Carbohydrates are chains of sugar molecules. Simple carbohydrates are chained only a few molecules in length. They are easily broken down into single molecules providing quick and short energy.
Complex carbohydrates are long chains. They have many sugars attached and are often folded into different shapes, normally for storage. These carbohydrates provide a slow and steady release of energy as their break-down is slower and prolonged.
To simplify: eat complex carbohydrates as they have the most nutritional value. Try to limit simple carbohydrates.
Simple carbohydrates are sugary and they make body fat if they are not burned up completely and immediately. Complex carbohydrates (such as vegtables and whole grain bread) digest slower and take longer to burn off. They tend not to make the body fat unless eaten in large quantities and not burned off.