Dear Dietitian – What are whole grains and how do they relate to fiber intake?
I am confused about whole grains. Some information tells me to eat lots of whole grains, but others say fiber is important in a healthy diet. Which is it?
You ask a good question. I recently bought a loaf of bread that advertised “20 grams of whole grains per serving” and “a good source of fiber.” What does this mean? According to the Food and Drug Administration (FDA), a whole grain must contain all the components of a grain kernel: the bran, germ, and endosperm.
Whole grains include, but are not limited to, whole wheat, barley, rye, oatmeal, popcorn, brown rice, and wild rice. These foods are rich in nutrients, including B vitamins and fiber. Refined grains, such as white bread and white rice, do not include all of the grain kernels. In the refinement of these grains, nutrients and fiber are removed. Nutrients are added back in the enrichment process, but fiber is not.
Enrichment of refined grains is required in the United States to prevent nutrient deficiencies. Centuries ago, people in the Far East who relied on white rice for 80% of their energy intake, developed a neurological disorder known as beriberi, which literally means “I can’t; I can’t.” This disorder left many paralyzed, weak, and with mental confusion. Extensive research uncovered the root of beriberi to be a lack of thiamin (vitamin B1) due to the refinement process.
There is very little government regulation for whole grain food labeling. However, the Whole Grains Council, a nonprofit group, has developed guidelines to aid in truth in advertising. For example, a product with the “100% Whole Grain” stamp must have at least 16 grams of whole grains per serving.
In contrast, there are regulations for fiber claims. A “high in fiber” claim must contain 5 grams or more fiber per serving. A claim that a food is “a good source of fiber” must contain at least 2.5 grams of fiber per serving.
Remember, the focus is on fiber. Scientific studies have shown a positive link between high fiber diets and the prevention of chronic diseases, such as diabetes, heart disease, and high blood pressure. These studies do not isolate one particular type of fiber or whole grain, but rather, all sources of fiber are included. These food sources include grains, fruits, vegetables, and even manufactured sources known as functional fiber. The bottom line is food that contains whole grains is not necessarily high in fiber.
While whole grains are your best choice in the grain food group, many plant products are rich in fiber and nutrition, including nuts, seeds, fruits, and vegetables. Set your goal of fiber intake to at least 20 grams per day. If you’re not used to eating a high-fiber diet, begin with 10 grams a day and work up to a goal of 20- 35 grams each day. Remember to drink plenty of water when increasing fiber intake to ease the digestive process.
Until next time, be healthy!