Grains are an important part of a healthy diet, providing energy, nutrients and fiber. However, there is some debate around how much grains we should be eating each day. The standard recommendation from the USDA Dietary Guidelines is to make half your grains whole grains and limit refined grain intake. But how does this translate into actual serving sizes and cups per day?
What are grains?
Grains are the edible seeds of certain grass crops. This includes foods like wheat, rice, oats, corn, rye, barley and quinoa. Grains fall into two main categories:
Whole grains
Whole grains contain the entire grain kernel, including the nutrient-dense bran, germ, and endosperm. Examples of whole grains include whole wheat, brown rice, oatmeal, quinoa, buckwheat and barley.
Refined grains
Refined grains have been milled to remove the bran and germ, leaving only the endosperm. This process extends the shelf life of grains but removes dietary fiber, iron and many B vitamins. Examples of refined grains include white flour, white bread, and white rice.
Recommended daily grain intake
The Dietary Guidelines for Americans recommend the following daily grain intake:
- 6 ounce equivalents for women
- 8 ounce equivalents for men
Half of this should be whole grains. An ounce equivalent is defined as:
- 1 slice of bread
- 1 ounce of dry cereal
- 1⁄2 cup cooked cereal, rice or pasta
So in cups per day, the recommendations would be:
- Women: 3 cups of whole grains and 3 cups of refined grains
- Men: 4 cups of whole grains and 4 cups of refined grains
This translates to:
For women:
- 3 cups of whole grains like oats, brown rice, quinoa
- 3 cups of refined grains like white rice, white pasta, white bread
For men:
- 4 cups of whole grains like whole wheat bread, barley, whole grain cereal
- 4 cups of refined grains like white bread, white rice, crackers
So in summary, the recommendations are:
Women
- 3 cups whole grains
- 3 cups refined grains
Men
- 4 cups whole grains
- 4 cups refined grains
What counts as a cup of grains?
Here are some common grain serving sizes that count as 1 cup:
- 1 slice of bread
- 1⁄2 cup cooked rice, pasta or cereal
- 1 ounce of dry cereal (check cereal box for weight)
- 1 6-inch tortilla
- 5-6 crackers
- 1⁄2 large bagel
- 1 small muffin (2.5″ diameter)
- 1 cup of ready-to-eat cereal flakes
For convenience, here is a quick reference table of grain serving sizes that count as 1 cup:
| Grain Food | Serving Size |
|---|---|
| Bread | 1 regular slice |
| Cereal (cooked) | 1⁄2 cup cooked oatmeal, grits, bulgur, etc. |
| Cereal (ready-to-eat) | ~1 cup flakes or rounds |
| Cereal (dry) | 1 ounce by weight |
| Crackers | 5-6 regular crackers |
| Pasta or rice (cooked) | 1⁄2 cup cooked |
| Tortilla | 1 6-inch tortilla |
| Bagel | 1⁄2 large bagel |
| Muffin | 1 small muffin (2.5″ diameter) |
As shown in the table, many common grain foods contain at least 1 cup equivalent of grains per serving. Keep these serving sizes in mind when planning meals and snacks to meet your daily grain needs.
Tips for reaching daily grain intake
Here are some tips to help meet your recommended daily intakes within your calorie needs:
Fill half your grain servings with whole grains
Aim for at least half your recommended grain intake to be whole grain sources like 100% whole wheat bread, brown rice, oats and quinoa. Whole grains provide more fiber, vitamins and minerals than refined grains.
Enjoy whole grains at breakfast
Easy options include oatmeal, whole grain cereal or whole wheat toast. Whole grain pancakes and waffles are also a tasty choice.
Choose whole wheat bread and tortillas
For sandwiches and wraps, select 100% whole wheat bread or small 100% whole wheat tortillas instead of white refined options.
Swap white rice for brown rice
In stir-fries, salads, soups and side dishes, nutty brown rice can easily replace white rice. Quinoa and barley also make flavorful whole grain alternatives.
Snack on air-popped popcorn
Popcorn is a whole grain snack that counts toward your daily total. Stick to lower-fat versions to keep calories in check.
Look for whole grains in ready-to-eat cereals
Check the ingredients list and choose whole wheat, oats or other whole grains as the first ingredient. Avoid cereals with high sugar content.
Bake with whole wheat flour
Substitute up to half of the white flour called for in recipes with whole wheat flour for muffins, quick breads and some cookies.
Read labels to identify whole grains
Terms like “whole grain,” “whole wheat” and “oats” indicate more nutritious whole grain products.
Health benefits of whole grains
Consuming enough whole grains as part of a healthy diet offers several benefits:
- Rich in nutrients – Whole grains provide B vitamins, minerals like iron and magnesium, fiber and antioxidant phytochemicals.
- Aid digestion – Fiber content helps promote regularity and healthy gut bacteria.
- Help manage weight – The fiber and nutrients in whole grains support satiety and balanced blood sugar.
- Reduce disease risk – Eating whole grains is associated with reduced risk of heart disease, stroke, type 2 diabetes and some cancers.
- Versatile ingredients – Whole grains like oats, quinoa, brown rice and barley can be enjoyed as porridge, in salads, in soups and more.
However, keep in mind that grains should still be balanced with adequate fruits, vegetables, proteins and healthy fats in your diet. Moderation is important, even with healthier whole grains.
Are grains necessary in the diet?
Grains are a staple food for many around the world and an important source of nutrients in the diet. Technically, they are not considered an “essential” part of the diet that you cannot live without, like fats, carbohydrates, protein, vitamins and minerals.
However, eliminating grain foods completely or severely restricting intake is not recommended, as this can make it challenging to meet nutritional needs. Grains provide:
- Carbohydrates – The primary source of glucose for energy.
- Fiber – For digestive and heart health.
- B vitamins – For converting food into energy.
- Iron – For blood and muscle health.
- Magnesium – For bone health and enzyme function.
If you avoid grains, you’ll need to get these nutrients from other foods like starchy vegetables, fruits, beans, nuts, seeds, eggs and lean meats. Work with a registered dietitian to create a healthy grain-free eating pattern if desired.
Risks of eating too many grains
While whole grains can be part of a healthy diet, eating too many refined grains and grain-based foods may increase risks:
Weight gain
Overeating grains, especially refined grains, can contribute excess calories and lead to weight gain over time. Products made with refined grains like white bread, crackers and pastries often lack nutritional value and can quickly add up in calories.
Blood sugar spikes
Refined grains have a high glycemic index, meaning they cause rapid spikes in blood sugar. This can increase risk of insulin resistance over time. Whole grains have a lower glycemic index.
Nutritional deficiencies
Grain-heavy diets may displace other healthy foods like vegetables, fruits and lean proteins, potentially leading to deficiencies in nutrients like vitamin C, folate and iron.
Digestive issues
Some people see improvements in digestive symptoms like bloating and discomfort when reducing grain intake, especially gluten-containing grains.
To reduce risks, emphasize whole grains, limit refined grains, and ensure your diet has a variety of healthy foods like vegetables, fruits, proteins and healthy fats. Moderation and balance is key.
Grain recommendations for different diets
Here are the typical grain recommendations for some common diet patterns:
Ketogenic diet
This very low-carb diet limits grains to about 2-4 ounces per day, focusing mainly on low-carb vegetables, meats, eggs, nuts and seeds.
Paleo diet
Grains are not permitted on the paleo diet, which emphasizes meat, fish, eggs, vegetables, fruits, nuts and healthy fats.
Gluten-free diet
Gluten-free diets exclude all grains containing gluten. This includes wheat, barley and rye. Allowed grains include rice, corn, quinoa, oats and millet.
Low-FODMAP diet
This diet limits certain carbs that can trigger digestive issues. Some grains like wheat, rye and barley are limited in the initial elimination phase.
Vegetarian and vegan diets
Grains take on greater importance for protein, iron and zinc in plant-based diets. Focus on incorporating a variety of whole grains.
Should you eat grains if you have diabetes?
It’s a common myth that people with diabetes should avoid eating grains. In fact, grains can be part of a balanced diabetes diet:
- Focus on high-fiber whole grains that have less impact on blood sugar.
- Pair grains with protein, fat or fiber to slow digestion and glucose release.
- Limit refined grains and stick to controlled portion sizes.
- Monitor your blood sugar levels when introducing new grain foods.
- Individualize your carbohydrate intake based on your own blood sugar response.
Work with a registered dietitian knowledgeable in diabetes care to incorporate appropriate grain choices into your meal plan in controlled amounts that best support your blood sugar goals.
Setting daily grain goals
Here are some tips for fitting your recommended daily grain intake into a healthy, balanced diet:
- Aim to get at least half your grains from whole grain sources for the nutrients and fiber.
- Read labels and check ingredients lists to identify whole grain products.
- Measure portion sizes using measuring cups and food scales until you can eyeball servings accurately.
- Spread grain servings throughout the day in meals and snacks.
- Pair grains with protein sources such as eggs, lean meats or beans.
- Enjoy grains in moderation as part of an overall varied diet focused on vegetables, fruits, lean proteins, legumes, nuts and healthy fats.
- Consider needs for grains if following a special diet for health or personal reasons.
- Consult a registered dietitian if needed for guidance on grain intake tailored to your individual nutritional needs.
While grains can be incorporated into a healthy diet, keep in mind that focusing just on daily grain quantities is less important than your overall eating pattern. Develop healthy habits around whole foods, balanced nutrition and controlled portions for your long-term health.
Conclusion
The standard recommendations for daily grain intake are around 3-4 ounce equivalents for women and 4-5 ounce equivalents for men. This equates to roughly 3 cups of grains per day for women and 4 cups for men. At least half of these servings should come from whole grain sources for optimal nutrition.
There are many healthy ways to meet daily grain recommendations, such as whole grain breakfast cereals, whole wheat bread products, oatmeal, quinoa, brown rice and popcorn. Reading labels, measuring portions and being aware of serving sizes can help. But grains should still be balanced with other healthy foods as part of an overall nutritious diet, while limiting refined grains. Focus on developing healthy lifelong eating habits, rather than fixating solely on individual foods or macronutrients like grains.
