Healthy grain foods linked to improved diet quality and metabolic markers

With so much confusion around what makes a grain food truly healthy, new research now offers a clearer picture: a combination of grain foods can support better nutrition and metabolic health when they deliver on nutrient density. A new study published in Nutrients, which analyzed the diets of more than 14,000 Americans over five years, found that both whole and refined grain foods play a role in improved diet quality, nutrient intake and everyday accessibility.

Conducted by researchers at the Center for Public Health Nutrition at the University of Washington, the peer-reviewed study analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2017 to 2023. The analysis found that many everyday grain foods – including some breads, cereals and tortillas – ranked surprisingly high for nutrient density and affordability. The findings offer a more nuanced view of grain foods, moving beyond assumptions and highlighting a broader range of options that can support health.

Using two new nutrient profiling models to evaluate carbohydrate quality and overall nutrient density, the Carbohydrate Food Quality Score CFQS-3 and the Nutrient Rich Food (NRF9.3) index, the study identified which grain foods qualify as "healthy grain foods" based on higher levels of fiber, protein and essential nutrients, and lower amounts of added sugars, saturated fat and sodium. This approach revealed that both whole and refined grain foods can meet the mark, contributing meaningfully to diet quality and health. People who consumed more of these healthy grain foods had better overall nutrient intake, healthier eating patterns and more favorable markers of metabolic health.

Key findings include:

• Improved diet quality and nutrient intake. People who consumed more healthy grain foods had better overall diet quality and higher intakes of fiber, protein, iron, calcium, potassium and magnesium.
• Includes both whole and refined grain foods. Both types scored highly for nutrient density, with many refined or enriched options – like certain breads, cereals and tortillas – delivering strong nutritional value alongside whole grain choices.
• Part of healthier overall eating patterns. People who ate the most healthy grain foods also consumed more fruits, vegetables and lean proteins, suggesting these grain foods may support or reflect broader healthy habits.
• Linked to better metabolic health. Adults with higher intakes of these grain foods were less likely to be obese and had lower fasting insulin levels, a key marker of metabolic function.
• No added cost. Healthy grain foods were no more expensive than less healthy options and were often more affordable per gram or calorie.

"Healthy grains are a critical component of healthy diets" said Dr. Adam Drewnowski, Professor of Epidemiology at the University of Washington. "Our evaluation took whole grain content into account, along with fiber, vitamins and minerals. By delivering key nutrients such as fiber, iron, B vitamins and folate, grain foods can make a meaningful contribution to healthier eating patterns among all population groups."

As nutrition guidance continues to evolve, this study adds important clarity around the role of grain foods in supporting public health. The findings highlight the value of balance – not just in overall eating patterns, but in the types of grain foods we include. Recognizing the nutritional contributions of both whole and refined/enriched options offers a more inclusive and realistic path to better outcomes for Americans' diet and overall health. To learn more, visit GrainFoodsFoundation.org.

This study was supported through an unrestricted grant from the Grain Foods Foundation (GFF), a nonprofit organization dedicated to nutrition science and education to better understand the role of grain foods in healthful diets. GFF had no influence over the study design, data analysis or interpretation of findings.