Dear Lynn:

What are the differences between simple and complex carbohydrates? Which should be avoided on a low-carbohydrate diet? Do liquid carbohydrates count? Thanks for any information you can provide.
Patty

Dear Patty:

Many people are confused about the differences between simple and complex carbohydrates -- and many of the popular weight-loss books seem to do all they can to muddy the waters even further.

Carbohydrates are one of three macronutrients that provide calories in our diets. 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 biking, walking and running up the stairs.

Carbohydrates are considered simple or complex based upon their chemical structure.

• Both types contain four calories per gram,
• and both are digested into a blood sugar called glucose, which can then be used to fuel our bodies for work or exercise.

Somehow, simple carbohydrates have become known as the "bad" carbohydrates, while complex carbohydrates seem to be designated as the "good" carbohydrates. But there is no real scientific or nutritional justification for these descriptions.

• Simple carbohydrates are digested quickly. Many simple carbohydrates contain refined sugars and few essential vitamins and minerals. Examples include fruits, fruit juice, milk, yogurt, honey, molasses, maple syrup and sugar.
• Complex carbohydrates take longer to digest and are usually packed with fiber, vitamins and minerals. Examples are vegetables, breads, cereals, legumes and pasta.

Most experts recommend that 50-60 percent of the total calories in our diet come from carbohydrates. The bulk of the carbohydrate choices should be complex carbs and most of the simple carbohydrate choices should come from fruits and milk or yogurt, which also contain vitamins and minerals. Avoid making the bulk of your carbohydrate choices from refined foods high in sugar, since they are usually low in the nutrients we need to maintain health and energy levels.

Sincerely,
Lynn Grieger, RD, CD, CDE

RESOURCES:

• Elements of Nutrition: Carbohydrates
• Elements of Nutrition: Protein
• Which fats are healthy?
• Get carb-rich recipes with the Recipe Finder.