Whole Grains

Key takeaways

• Dietary Guidelines advice: make at least half your grains whole grains
• Grains at 2,000 calories: 6 ounce-equivalents a day, at least 3 whole
• Most useful single change: Swap the version of a food you already eat rather than adding new ones.
• Commonest mistake: Trusting a brown color, which can come from caramel coloring or molasses.
• See a doctor if any of the signs under "When to get help" below apply to you.

Why it matters

They carry most of a grain's fiber and micronutrients, and higher intakes are linked to lower heart disease and type 2 diabetes risk.

The numbers, in one place

Published figures for Whole Grains

Measure	Figure
Dietary Guidelines advice	make at least half your grains whole grains
Grains at 2,000 calories	6 ounce-equivalents a day, at least 3 whole
One ounce-equivalent	1 slice of bread, 1/2 cup cooked rice, pasta or oatmeal, or 1 cup ready-to-eat cereal
Oat beta-glucan in the FDA health claim	3 g a day
Label check	the first ingredient should say whole

What helps

• Swap the version of a food you already eat rather than adding new ones
• Try whole-wheat pasta and brown rice mixed half and half at first
• Keep oats in the pantry as one of the cheapest whole-grain breakfasts there is
• Choose bread where whole-wheat flour is the first ingredient

What to avoid

• Trusting a brown color, which can come from caramel coloring or molasses
• Assuming "made with whole grain" means mostly whole grain
• Cutting grains out entirely rather than switching the type

In depth

Every grain kernel has three parts. The bran is the fiber-rich outer layer, carrying B vitamins, minerals and antioxidants. The germ is the small embryo that would sprout into a new plant, rich in healthy fats, vitamin E and B vitamins. The endosperm is the large starchy center that feeds the seedling. A whole grain keeps all three. Refining removes the bran and germ to make white flour and white rice, which keep longer and have a softer texture but lose most of the fiber and many nutrients.

In the US, most refined grain products are enriched, meaning some of the B vitamins and iron lost in milling are added back, and folic acid is added too. Enrichment has helped prevent certain birth defects. It does not, however, replace the fiber, magnesium, vitamin E and many other compounds lost with the bran and germ. That is why the Dietary Guidelines advise making at least half of your grains whole rather than cutting grains out altogether.

Whole grains are digested more slowly than refined grains, partly because the bran and fiber physically slow access to the starch. That tends to produce a gentler rise in blood glucose and helps you feel full for longer. Some whole grains also have specific benefits: the soluble fiber beta-glucan in oats and barley helps lower LDL cholesterol, which is why the FDA allows a health claim for these foods when they supply enough beta-glucan.

Signs and symptoms

• Constipation and low fiber intake
• Feeling hungry again soon after meals built on white bread, rice or pasta
• Diet heavy in refined grains with few beans, vegetables or fruit
• Bloating, diarrhea or weight loss after eating wheat, barley or rye, which needs medical assessment

Causes and risk factors

• Habit and taste preference for white bread, rice and pasta
• Confusing labels such as "multigrain," "wheat" or "made with whole grain"
• Belief that whole grains take too long to cook
• Cost or limited availability of whole-grain versions in some stores
• Low-carbohydrate diets that remove grains entirely
• Celiac disease or wheat allergy, which narrow the range of grains you can eat

How it is checked

Whole-grain intake is not measured by any test. To check your own, look at the grain foods you eat in a typical day and see whether at least half are whole. On the label, look for "whole" in the first ingredient, such as whole wheat, whole oats or brown rice, or for a whole-grain stamp from an industry group, while remembering that the stamp is voluntary.

If grains seem to cause symptoms, your doctor may test for celiac disease with a blood test, and sometimes a biopsy taken during an upper endoscopy. These tests only work while you are still eating gluten, so do not remove it from your diet before you have been tested. Wheat allergy is diagnosed separately, usually by an allergist.

Related topics

• Carbohydrates and Blood Glucose: Sorting the Evidence From the Noise (Diabetes)
• Snacking: What Published Guidance Supports (Healthy Recipes)
• Reading the Nutrition Facts Label: What the Evidence Actually Says (Food Safety)
• Diet and Eye Health: Sorting the Evidence From the Noise (Eye Health)

Where to go next

• A Q and A on Whole Grains
• Whole Grains in Five Minutes
• Nutrition: The Complete Guide
• The Evidence on Food Labels, Without the Hype
• What the Guidance Really Says About Meal Planning

When to get help

People with celiac disease must avoid wheat, barley and rye and should choose oats labeled gluten-free. See your doctor for persistent bloating, diarrhea or weight loss after eating grains, which should be tested for celiac disease before you remove gluten from your diet. Call 911 for signs of a severe allergic reaction after eating, such as trouble breathing or swelling of the throat.

Where this comes from

• Dietary Guidelines for Americans — Dietary Guidelines for Americans, 2020-2025
• National Institute of Diabetes and Digestive and Kidney Diseases — Eating, Diet, and Nutrition for Celiac Disease

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.