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A new study shows that both whole and fortified grains can help Americans eat better, weigh less, and improve insulin levels, offering an affordable, accessible path to better health.

Review: Healthy Grains in Healthy Diets: The Contribution of Grain Foods to Diet Quality and Health in the National Health and Nutrition Examination Survey 2017–2023. Image Credit: sisi2017 / Shutterstock

In a recent study published in the journal Nutrients, researchers developed and leveraged two novel scoring methodologies to investigate the relative health and nutritional benefits of several different grain-based foods. The study then analyzed dietary data from over 14,000 Americans and found that individuals who consumed more “healthy” grains, as defined by either scoring methodology, had significantly higher overall diet quality.

Notably, consumption of these healthy grains was associated with lower rates of obesity and lower fasting insulin levels, though the study’s cross-sectional design limits causal conclusions. Importantly, the study compared consumers of “healthy” grains with those consuming fewer or no healthy grains, not with non-grain consumers.

Background

Dietary guidelines worldwide, including the Dietary Guidelines for Americans, emphasize the importance of grain foods. These guidelines often recommend that at least half of all grain intake, not carbohydrate intake, should come from whole grains, noting that these foods are also crucial sources of fiber, B vitamins, folate, and essential minerals.

Unfortunately, the modern food landscape is filled with thousands of grain products, making it challenging for consumers to make informed choices and identify the “healthier” option. Conventional carbohydrate quality assessment methods are often too simplistic, focusing only on fiber and sugar content while ignoring the value of whole grains or fortification with vitamins and minerals.

These insufficiencies necessitate the development of novel metrics capable of holistically scoring various grain sources, thereby providing consumers with the knowledge required to safeguard their health.

Distribution of 1244 grain foods in USDA FNDDS 2017–2018 by WWEIA food category.

About the study

The present study aims to address this need through the development of more comprehensive tools for identifying healthy grains, and additionally, to quantify their contribution to overall diet quality and health outcomes in a large, nationally representative sample of the US population.

The cross-sectional study analyzed data from 14,720 participants (aged six and older; children = 3,795 individuals) from the National Health and Nutrition Examination Survey (NHANES; 2017–2023). Socio-demographic (age group, sex, race/ethnicity, family income) and dietary data (What We Eat in America [WWEIA]) were collected for stratification and novel methodology testing, respectively.

Data from the Food and Nutrient Database for Dietary Studies (FNDDS) was used to evaluate the nutritional content of 1,244 different grain foods. The novel scoring systems themselves comprised:

• •Carbohydrate Food Quality Score (CFQS-3): A 3-point score based on three key ingredient-related factors: whole grain content, fiber-to-carbohydrate ratio, and added sugar-to-carbohydrate ratio.
• •Nutrient Rich Food Index for Grains (NRF9.3g): A nutrient-density score that balances nine beneficial nutrients (protein, fiber, B vitamins, folate, iron, etc.) against three nutrients to limit (added sugar, sodium, saturated fat).

These scores were used to subclassify grain consumers and compare their overall diet quality, leveraging the Healthy Eating Index (HEI-2020) and a diet-level NRF score. The study also analyzed clinical health data from NHANES, including body mass index (BMI), waist circumference, fasting insulin, and cholesterol levels.

Study findings

The two novel scoring systems developed in this study identified different sets of grain products as “healthy,” depending on the method used. The ingredient-focused CFQS-3 score gave the highest ratings to cooked whole grains, cereals, and savory snacks, while, in contrast, the nutrient-density NRF9.3g score favored fortified products, identifying ready-to-eat cereals, breads, and rolls as the healthiest.

Despite these differences, the fundamental outcome remained consistent – consuming healthy grains (from either scoring system) was strongly linked to better overall diet quality and health. Consumers of healthy grains demonstrated significantly higher HEI-2020 scores than non-consumers, and this effect was found to be dose-dependent.

Clinical data validated these health benefits – after adjusting for demographic and lifestyle factors, consumers of healthy grains were less likely to have obesity and showed better metabolic health. Specifically, consumers were significantly less likely to be obese (34.6% vs. 41.1%, p < 0.0001) and had significantly lower fasting insulin levels (13.97 vs. 15.90 µU/mL, p < 0.001) than those consuming fewer or no healthy grains. These associations were reported specifically for consumers of CFQS-3-classified grains.

Importantly, these associations varied by demographic group. Consumers of CFQS-3 grains were more likely to be women, older adults, and individuals with higher incomes, while consumers of NRF9.3g grains were more likely to be Non-Hispanic Whites.

Contrary to common assumptions, healthy grains, especially those identified using the NRF9.3g score, were not more expensive per 100 grams or per 100 kcal. In fact, many fortified grain products were found to be both nutrient-dense and affordable.

Conclusions

The present study supports national dietary guidelines by demonstrating that consuming healthy grain foods is a powerful indicator of a high-quality diet and is associated with better health outcomes, including a lower prevalence of obesity. By developing two new, robust scoring systems, both of which identified grain products associated with significant health improvements, the research provides a more nuanced way to identify beneficial grain products beyond the conventional “whole vs. refined” dichotomy.

The findings have important implications for American and global dietary guidance, suggesting that public health recommendations should acknowledge the significant contribution that a wide range of healthy grains (including fortified cereals and enriched breads) make to diet quality. Notably, many of these nutrient-dense options are affordable and widely available, underscoring their importance as a practical and accessible tool for improving public health and democratising nutrition.

More than a decade after Mexico became one of the first countries to impose a tax on sugary sodas, the Health Ministry is set to launch a new campaign aimed at discouraging their consumption.

“Sometimes we think that health is only about care when we get sick and go to a health center or hospital,” President Claudia Sheinbaum said in announcing the campaign during her daily press conference on Tuesday. “[However,] health is related to care, prevention and particularly sugary drinks, soft drinks.”

Despite the tax, implemented in 2014, soft drink consumption is still excessive in Mexico, and the campaign will emphasize public education. Health Minister David Kershenobich said at the conference that Mexicans drink an average of 166 liters of soda per year, putting Mexico among the top countries for sugary drink consumption globally. 

Seven in 10 children and adolescents consume soft drinks daily, even with breakfast, according to Kershenobich. He stressed that high levels of soda consumption are linked to the development of diabetes and cardiovascular disease, with a single 600 ml soda containing between 12 and 15 teaspoons of sugar. 

In 2024, 190,000 deaths in Mexico were attributed to heart disease and 112,000 to diabetes. 

“One wonders if we have a way to treat these people because we continue to have such a high mortality rate,” said Kershenobich. “And that’s where preventive programs come in.”

Junk food ban goes into effect in Mexican schools

The Health Ministry plans to implement prevention campaigns focused on healthy consumption and education on nutrition from early childhood starting next week.

Programs such as the government’s “Live Healthy, Live Happy” initiative, which was launched by Sheinbaum on Feb. 25 to reduce the consumption of junk food and sugary drinks among children, are key to changing societal habits and tackling chronic diseases, according to Kershenobich.  

Will the soda tax increase?

The emphasis at the press conference was on education, not taxation. But health experts from various institutions recommend introducing higher taxes on sugary drinks to reduce their consumption.  

Judith Senyacen Méndez, the deputy director of research at the Center for Economic and Budgetary Research, said that introducing a 20% tax on the drinks could drive down consumption by between 16% and 19%, based on empirical evidence.

Meanwhile, Iván Bremeunea, the coordinator of the Fundar Center of Analysis and Research’s Tax Justice Program, said a 20% tax could reduce obesity cases by up to 970,000, in addition to generating annual revenue of over 104 billion pesos (US $2.5 billion).

While Mexico’s one-peso-per-liter soda tax (about 10%) did in fact reduce consumption at first, Bremeunea said that the current levy is no longer effective and must be increased. He said that even a further 6% increase in soda prices could reduce obesity rates by 3.2%.

With reports from Instituto Mexicano de la Radio Noticias, Meganoticias, El Universal and El Economista

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