What Will Happen if You Don't Eat Enough Grains?

December 20, 2025 •

3 min read

According to the American Heart Association, at least half of your daily grain intake should be from whole grains. So, what will happen if you don't eat enough grains? The answer goes beyond just losing a food group; it can lead to a series of health complications, including nutritional deficiencies, digestive problems, and reduced energy levels.

Quick Summary

Insufficient grain consumption can lead to fiber, vitamin, and mineral deficiencies, causing digestive issues, fatigue, and other health problems. Replacing grains with nutrient-dense alternatives is crucial for maintaining a balanced diet and overall well-being. Understanding the role of grains and how to properly substitute them can help prevent negative side effects.

Key Points

Fatigue and Low Energy: Without grains, the body lacks its primary source of complex carbohydrates, leading to reduced energy and increased fatigue.
Nutrient Deficiencies: Avoiding grains can cause deficiencies in vital nutrients like B vitamins, iron, magnesium, and selenium, which are essential for various bodily functions.
Poor Digestive Health: The fiber found in whole grains is critical for regular bowel movements and a healthy gut microbiome; a lack of it can cause constipation.
Increased Heart Disease Risk: Eliminating grains can increase this risk.
Difficulty with Weight Management: Removing grains can increase cravings and overeating.
Challenges in Planning Meals: Maintaining a balanced diet without grains requires careful meal planning to ensure adequate replacement of lost carbohydrates and nutrients.
Impact on Specific Demographics: Certain groups, such as pregnant women, children, and individuals with a history of deficiencies, face higher risks when eliminating grains.
Not a Universal Solution: {Link: EatingWell https://www.eatingwell.com/article/7896583/is-a-grain-free-diet-healthy-heres-what-dietitians-say/}.

The Importance of Grains in Your Diet

Grains, particularly whole grains, are a fundamental part of a balanced diet for most people, supplying essential nutrients that fuel the body. They provide carbohydrates, which the body uses for energy, and are a good source of fiber, vitamins, and minerals. Whole grains contain the bran, germ, and endosperm, offering more nutritional value compared to refined grains where the bran and germ are removed. A diet lacking sufficient whole grains can lead to various negative health effects.

Impact on Energy Levels

Low grain intake can lead to fatigue and sluggishness due to insufficient carbohydrates, the body's main energy source. Whole grains provide sustained energy release due to their fiber content, helping to keep blood sugar stable and prevent energy crashes.

Risk of Nutritional Deficiencies

Grains are rich in B vitamins, iron, magnesium, and selenium. Folic acid is also often added to enriched grains. Without these, deficiencies can occur, impacting metabolism, nervous system function, and more. Replacing these nutrients often requires careful planning or supplements.

Compromised Digestive Health

Whole grains are a key source of dietary fiber, important for regular bowel movements and preventing constipation. Fiber also supports a healthy gut microbiome. A low-grain diet can reduce fiber intake, leading to digestive issues.

Refined vs. Whole Grains: A Comparison


Feature	Refined Grains	Whole Grains
Processing	Milled to remove bran and germ.	Contains the entire grain kernel: bran, germ, and endosperm.
Nutrient Content	Significant loss of fiber, B vitamins, and minerals.	High in fiber, B vitamins, iron, magnesium, and antioxidants.
Energy Release	Fast digestion causes blood sugar spikes and crashes.	Slower digestion provides steady, sustained energy.
Fiber Content	Low fiber, which can lead to constipation.	High fiber, promoting digestive health and regularity.
Example Foods	White bread, white rice, pasta.	Brown rice, whole wheat bread, oats, quinoa.

Potential Health Implications of Grain Avoidance

Heart Disease Risk: Whole grain consumption is linked to reduced heart disease risk; their absence can increase this risk.
Weight Management Issues: Fiber in whole grains promotes fullness, aiding weight management. Removing them can increase cravings.
Mental Health Impact: While some report mood improvements on grain-free diets, nutrient deficiencies can negatively affect mental health.
Risk for Specific Groups: Pregnant women, children, and individuals with a history of deficiencies face higher risks when eliminating grains.

How to Supplement Your Diet if Avoiding Grains

For those needing to avoid grains due to conditions like celiac disease, replacing lost nutrients is vital. Pseudocereals like quinoa and amaranth offer similar nutrition. Increasing fruits, vegetables, legumes, nuts, and seeds can help meet nutrient needs. A registered dietitian can assist in creating a balanced grain-free meal plan. For example, using amaranth as a base for a salad with lentils and leafy greens can help compensate for nutrients from grains.

Conclusion

Not eating enough grains, especially whole grains, increases the risk of fatigue, digestive problems, and nutrient deficiencies. A grain-free diet is generally not recommended unless medically necessary. The nutrients in grains are crucial for overall health. {Link: EatingWell https://www.eatingwell.com/article/7896583/is-a-grain-free-diet-healthy-heres-what-dietitians-say/}

Suggested Grain Substitutions Table


Item	Whole Grain Option	Grain-Free Alternative
Rice	Brown Rice	Cauliflower Rice
Pasta	Whole Wheat Pasta	Zucchini Noodles or Shirataki Noodles
Breakfast Cereal	Oatmeal or Whole Oats	Chia Seed Pudding or Grain-Free Porridge
Flour	Whole Wheat Flour	Almond Flour or Coconut Flour
Bread	Whole Grain Bread	Lettuce Wraps or Collard Green Wraps

Sources

American Heart Association: https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/nutrition-basics/whole-grains-refined-grains-and-dietary-fiber
Healthline: https://www.healthline.com/nutrition/grain-free-diet
EatingWell: https://www.eatingwell.com/article/7896583/is-a-grain-free-diet-healthy-heres-what-dietitians-say/

Note: Consult with a healthcare professional or registered dietitian before making significant changes to your diet.

Frequently Asked Questions

Yes, you can get sufficient fiber from other sources, such as fruits, vegetables, legumes, nuts, and seeds. However, it requires careful meal planning to ensure adequate intake.

Initial symptoms can include low energy, feelings of fatigue, digestive changes like constipation, and increased cravings for carbohydrates or sugary foods.

No, grains are not inherently bad. While refined grains are less nutritious, whole grains offer significant health benefits, including fiber, vitamins, and minerals.

Individuals with celiac disease or a diagnosed non-celiac gluten sensitivity should avoid grains containing gluten, such as wheat, barley, and rye. For others, medical consultation is recommended before eliminating grains.

Common replacements include starchy vegetables like potatoes and squash, pseudocereals like quinoa and amaranth, and non-grain flours made from nuts or seeds.

{Link: EatingWell https://www.eatingwell.com/article/7896583/is-a-grain-free-diet-healthy-heres-what-dietitians-say/}.

Grains provide carbohydrates that fuel the brain. Eliminating them without replacement can lead to mental fatigue and impact concentration. B vitamins found in grains are also vital for brain function.

Yes, if not replaced with other nutrient-dense foods, avoiding grains can lead to deficiencies in essential vitamins, minerals, and fiber, potentially causing malnutrition over time.

Whole grains contain the entire kernel, including the fibrous bran and nutrient-rich germ. Refined grains have these parts removed, which strips away much of the nutritional value.

For those with specific intolerances, it can reduce symptoms like bloating and inflammation. For the general population, most health benefits can be achieved by choosing whole grains over refined ones.