simple carbs have a very simple chemical structure, while complex carbs are well more complex, think of the difference between a straight line(simple carbs) and a road map( complex carbs) simple carbs are digested more quickly, and complex carbs take longer because of their more complex structure examples of simple and complex carbs... simple carbs includes,sucrose( table sugar), fructose, (fruit sugar), lactose(milk sugar) so foods that contain primarily these simpler forms of carbs are known as simple carbs, also simple carbs are found in cookies pastries, candy friut juice, etc... now for complex carbs typically contain more fiber, and have a more complex chemical structer that takes longer to digust, examples are, bread, cereal,pasta,potatoes,corn,peas,limabean s,kidney beans etc.... overall we need more complex carbs than simple that's not to say that simple carbs are bad. we just need less of then. The reason? complex carbs have more fiber vitamins,minerals and phyochemicals.. simple carbs tend to be more highly processed, remember milk contains simple carbs and we definitely need the calcium and vitD from milk,so you shouldn't avoid all simple carbs..and if your going on a low carb diet the key is not to go overboard and throw out all the essentail nutrients we need for health and optimum energy in pursuit of a low-carb eating plan.. hope this sums it up for you..... :bouncing: