I know that there is a difference between the carbs in sugary things and the ones found in grainy things. But what really is the difference? I know that sugars are simple carbs and things like bread have complex carbs, but why are the complex ones better for you, exactly? Does anyone know how they are different on the molecular level? What parts of complex carbohydrate molecules does your body use differently from the parts of simple ones?
And, to go along with that, why is it that your body gets so hyper off sugar and then burns it all up so that you have a huge crash? That doesn't happen with bread or pasta.
I just got to thinking about the whole Atkins thing and how people don't realize the difference between simple and complex carbs, and I realized that although I knew there was a difference, I don't know specifically what it is. We studied this a bit in AP Bio, but that was a few years ago, so my memory needs a refresher.
Edit - Here are some of the comments people have left so that you don't have to scroll through them all to get the pertinent info:
"'Many people are confused about the differences between simple and complex carbohydrates and many popular diet books seem to only make it more confusing.
Carbohydrates are one of three macronutrients in our diets that provide calories. The other two are protein and fat. Carbohydrates provide most of the energy needed in our daily lives, both for normal body functions such as heartbeat, breathing and digestion and for exercise such as cycling, walking and running.
Carbohydrates are considered simple or complex based upon their chemical structure and both types contain four calories per gram. Both are also digested into a blood sugar called glucose, which is then used to fuel our bodies for work or exercise.
In the past few years, simple carbohydrates have become known as the 'bad' carbs, while complex carbs seem to be designated as the 'good' ones. Although this is based on more hype than science, here are the reasons why:
Simple carbohydrates are digested quickly. Many simple carbohydrates contain refined sugars and few essential vitamins and minerals. Examples include fruits, fruit juice, milk, yoghurt, honey, molasses and sugar.
Complex carbohydrates take longer to digest and are usually packed with fibre, vitamins and minerals. Examples are vegetables, breads, cereals, legumes and pasta.
Most experts recommend that 50 to 60 per cent of the total calories in our diet come from carbohydrates. The bulk of the carbs we consume should be complex and most of the simple ones should come from fruits and milk or yoghurt, which also contain vitamins and minerals.
Avoid getting the bulk of your carbs from refined foods high in sugar, since they are usually low in the nutrients we need to maintain health and energy levels.'"
And therealslimjoce adds...
"In dieting, the biggest difference is between refined carbs and unrefined carbs. The sugar in a Twix is no difference chemically than the sugar in an orange -- both simple carbs. But since the sugar in the Twix has already been heavily processed and ground done into a fine white powder, your digestive system has no work to do before it enters your blood stream. Therefore it causes a huge insulin spike followed by an insulin slump, leaving you tired, cranky, and craving more sugar. On the other hand, the orange will take much longer for your body to convert to glucose (blood sugar).
People talk about foods' "glycemic index" or "glycemic load"; this is supposed to express how quickly the foods will impact your blood sugar. A higher index means it will cause a greater blood sugar spike (bad).
Here are some examples:
White bread>whole wheat bread
White rice>brown rice
If you stick to the unrefined carbs -- fruits, vegetables, whole grains, dairy -- your blood sugar will stay more stable and you won't experience as many cravings."