Dietary fiber, also known as roughage or bulk, includes all parts of plant foods that your body can't digest or absorb. Unlike other food components such as fats, proteins or carbohydrates — which your body breaks down and absorbs — fiber isn't digested by your body. Therefore, it passes relatively intact through your stomach, small intestine, colon and out of your body. It might seem like fiber doesn't do much, but it has several important roles in maintaining health.
Fiber is commonly classified into two categories: those that don't dissolve in water (insoluble fiber) and those that do (soluble fiber).
*** We are not going to worry about the differences between soluble and insoluble fiber for this week's challenge - we're just shooting for 25-30 total grams here - but if you'd like to research this topic more and share your insights with the rest of us, please feel free. ***
Fiber improves large intestine function and keeps the muscles of the large intestine strong. It speeds up the transit time of food and thereby helps prevent constipation. Fiber also lowers blood cholesterol, helps control diabetes, and plays a role in the prevention of colon cancer. Fiber is a very important component in weight control as well. Foods that contain fiber are typically low in fat, and one recent study showed that fiber may also block some of the digestion of fat and protein. In this study, U.S. Department of Agriculture (USDA) researchers fed a certain number of calories to all participants, but altered the fiber content of the meals. The results? Fewer calories were absorbed with increased fiber intake. When a man increased his fiber intake from 18 to 36 grams per day, he absorbed 130 fewer calories daily. When a woman increased her fiber intake from 12 to 24 grams per day, she absorbed 90 fewer calories daily. Over a year's time, this could add up to nine to ten pounds.
You must go slowly to give your GI tract time to adapt and drink lots of fluids to keep the fiber soft. Also, choose a variety of soluble and insoluble fiber-rich food sources: fruits, vegetables, whole grain breads and cereals, and legumes (beans and peas). Remember that brown rice and 100% whole wheat bread have more fiber than white rice or white bread. Eating the skins of your fruits and vegetables whenever possible can also help increase fiber intake.