Complex carbohydrates are found in plant-based, fiber-rich foods such as grains, legumes, seeds and vegetables. Although fiber passes through your body undigested, it has an important function in supporting weight loss and maintaining a healthy weight for your body type. There are two types of dietary fiber, soluble and insoluble. Both of these play key roles in facilitating healthy digestion and balancing blood glucose levels. Fiber helps bulk up digested food in the intestines. This slows digestion, allowing glucose to be released into the blood at a slower, steadier rate for balanced energy production.
Dietary fiber is an important component of whole grains such as wheat, rye, barley and quinoa. Brown, unpolished rice is also a whole grain. These foods are complex carbohydrates because they still contain their bran or germ layer, which contains fiber and nutrients. However, the University of Maryland Medical Center notes that when whole grains are transformed into processed, white flour and white rice, this fiber-rich layer is removed leaving behind simple, starchy carbohydrates. Eating whole grain breads, pastas and brown rice instead of the white varieties can help you to lose weight and get lean.