Carbs are made up of sugar, starches, and cellulose that give your brain and muscles fuel. Its primary function is to supply energy quickly. Complex carbs are long chains of molecules that are more complex than simple carbs. Carbohydrates are in beans, veggies, grains, breads and pasta. Complex carbs take longer to brake down. Complex carbs are high in fiber and low in calories and also low in fat. Complex Carbohydrates have a longer life span than simple carbs. These keep energy levels even for longer periods of time. These carbs also give a real feeling of fullness. They are stored in the liver and muscles as glycogen. Simple carbs are molecularly simple with their single double sugar molecules. This means they release quickly into the bloodstream but have a short life span. Fruits, processed sugar, and processed foods have simple carbohydrates. Simple carbs are lower in fiber and higher in calories than complex carbohydrates.