Hope Warshaw / Special To The Washington Post

Q: Do all whole grains contain dietary fiber? What are other sources of fiber?

A: The questions seem simple, but they’re not. Answering them, however, is important because they focus on two healthful eating goals: 1) Eat more whole grains and 2) Eat more dietary fiber.

Both are supported by research evidence. Eating sufficient whole grains, as part of a healthful eating plan, can protect against cardiovascular disease and help maintain a healthful body weight. Some research shows that eating enough whole grains can reduce insulin resistance and Type 2 diabetes.

Research on dietary fiber shows that a sufficient amount can protect against cardiovascular disease, obesity and Type 2 diabetes, and can promote digestive health.

About whole grains

Whole grains contain the essential parts and naturally occurring nutrients of the entire grain seed — the bran, germ and endosperm. Oats and barley are whole grains. Whole-wheat flour is a whole-grain ingredient found in foods such as whole-wheat bread and pasta.

Whole grains are just one source of dietary fiber. Whole grains and foods that are made with whole-grain ingredients provide some dietary fiber, but the amounts vary widely. They also provide other essential nutrients. Barley and bulgur contain a good bit of fiber, while brown rice and quinoa contain minimal amounts. But they’re all healthful sources of whole grains.

According to the Whole Grains Council, Americans, on average, eat less than one serving of whole grains a day. Over 40 percent of Americans never eat any whole grains. Surprising? Not with all the bread, baked goods and pizza dough made with refined flour that we eat. The Dietary Guidelines for Americans recommend making half your grains whole. (Catchy, eh?) That’s 48 grams per day.

About dietary fiber

Dietary fiber includes the portions of plant-based foods that are not digested plus beneficial fibers added by manufacturers. Our foods contain hundreds of various fibers — some help with digestion and regularity, others improve blood fats and others help with weight control. You need all types. Dietary fiber is a nutrient found in whole grains, legumes (beans and peas), fruits and vegetables. To eat enough fiber, get it from all food sources.

Most Americans get nowhere close to the 25 grams per day recommended for adults. No surprise! We don’t eat nearly enough fruit, vegetables, legumes and, yes, whole grains with fiber.

“Because fiber is a nutrient, it’s required to be listed on most nutrition facts labels. It’s easy to spot and count up,” says Joanne Slavin, dietitian and nutrition professor at the University of Minnesota and a member of the 2010 Dietary Guidelines Advisory Committee. But whole grain is simply a component of food, not a nutrient, which is why it’s not accounted for on the nutrition facts label, she says. That can make it harder to track.

Don’t translate the message to eat more whole grains and dietary fiber to mean “eat more.”

“You’ll hit your whole grain and fiber goals without excess calories if you swap and substitute,” says Carlene Thomas, a registered dietitian with the private practice Healthfully Ever After in Leesburg, Va.