Nutrition expert Dr. Allan Spreen answers common questions about diet and fitness:

Q: What is the difference between "refined" and "unrefined" carbohydrates and is it that significant?

A: Carbohydrates are the "quick energy" fuel suppliers for the body. These foods burn rapidly for energy, and though they are themselves poorly stored (as glycogen), they are readily converted to fat (which, as you know, is all too often readily stored).

There are simple and complex carbohydrates (commonly called "carbs"). The former consist of the sugars, fruits and sweet vegetables, while the latter contain the starches like breads, cereals, grains, pastas and starchy vegetables. Complex carbs consist of sugar molecules linked together by certain chemical bonds and require an enzyme to break them down to sugar for our bodies to utilize.

"Refining" is a process that can apply to simple or complex carbs. It is the act of removing fiber, nutrients, usually water, and other items contained within the food in its natural state. The purpose is usually to improve shelf life or concentrate taste. Unfortunately, in so doing the sugars are concentrated, which can cause our blood sugar levels to change more rapidly than normal, allowing swings in sugar levels that can cause symptoms (fatigue, irritability, appetite and many others). In addition, nutrients are removed that are needed for the utilization of the sugar that remains in the refined product. This means that those nutrients must be taken from body stores instead of the food, which over time can lead to deficiencies.