Scientists urge nutrition security for better US diet quality and health equity

15 Jul 2024 --- Researchers call for a “new prioritization of nutrition security” to achieve health equity and overcome nutritional disparities. Although diet quality improved “modestly” among US adults between 1999 and 2020, they caution that the proportion with poor diet quality remains high.

Moreover, they note that dietary disparities persist and, in some cases, worsen. For example, the proportion of people with poor nutritional quality decreased from 48.8% to 36.7%, but this share decreased at a much lower rate among individuals with a lower income, from 51.8% to 47.3%. 

In addition, the researchers note that poor diet quality persisted among people experiencing food insecurity, while rates decreased for food-secure people (48% to 33%). 

“While we’ve seen some modest improvement in US diets in the last two decades, those improvements are not reaching everyone, and many people in the country are eating worse,” says Dariush Mozaffarian, director of the Food is Medicine Institute at US Tufts University and co-author of the study. 

“Our new research shows that the nation can’t achieve nutritional and health equity until we address the barriers many US citizens face when accessing and eating nourishing food.” 

The researchers base their diet quality assessment on the American Heart Association (AHA) guidelines. 

Defining diet quality  
The study, published in the Annals of Internal Medicine, evaluates the diet quality of 51,703 participants of the 1999 – 2020 National Health and Nutrition Examination Survey. All adults completed at least one valid 24-hour dietary recall, while 72.6% completed two recalls. 

Poor diet was defined as less than 40% adherence to the AHA 2020 guidelines, which are based on a higher intake of fruits, vegetables, whole grains, fish and shellfish, nuts, seeds and legumes and a lower consumption of sugar-sweetened beverages, processed meat, saturated fat and sodium. 

The researchers set intermediate diet quality at 40% to 79.9% adherence and ideal at least 80% adherence.

The study also used the Healthy Eating Index 2015 and energy-adjusted consumption of their components and other individual food groups and nutrients. 

AHA guidelines on diet quality include higher intake of fruits, vegetables, whole grains, fish and shellfish, nuts, seeds and legumes.Dietary improvements 
In addition to fewer individuals with poor diet quality, the researchers found higher shares of people with intermediate diet quality (from 50.6% to 61.1%) and ideal diet quality (0.66% to 1.58%). 

Regarding specific changes, the researchers found higher consumption of nuts or seeds, whole grains, poultry, cheese and eggs. Moreover, they noted a lower intake of refined grains, drinks with added sugar, fruit juice and milk. 

At the same time, the total intake of fruits and vegetables, fish or shellfish, processed meats, potassium and sodium remained relatively stable. 

“While some improvement, especially lower consumption of added sugar and fruit drinks, is encouraging to see, we still have a long way to go, especially for people from marginalized communities and backgrounds,” comments Junxiu Liu, the study’s first author, who was a postdoctoral scholar at the Friedman School of Nutrition Science and Policy, US, at the time of the study.

Inequitable access 
The authors also compared diet quality across age, sex, race and ethnicity, education, income, food security, participation in the Supplemental Nutrition Assistance Program (SNAP) and health insurance coverage. 

They found the most significant improvements among “younger adults, women, Hispanic adults and socially advantaged groups characterized by higher levels of education, income, food security and access to private health insurance.” 

Meanwhile, the study notes that nearly half of non-Hispanic black adults and adults from socially disadvantaged backgrounds still have poor diets. The authors stress that nutritional disparities may increase health risks. 

“We face a national nutrition crisis, with continuing climbing rates of obesity and type 2 diabetes,” emphasizes Mozaffarian. 

The authors stress that nutritional disparities between population groups may increase health risks.“These diseases afflict all US citizens, but especially those who are socioeconomically and geographically vulnerable. We must address nutrition security and other social determinants of health, including housing, transportation, fair wages and structural racism to address the human and economic costs of poor diets.”

Recently, a new study by the US Pennsylvania State University revealed that the number of US children experiencing food and water insecurity more than doubled between 2005 and 2020. This research also found that black and Hispanic children were several times more likely to face this situation. 

“National nutrition crisis” 
The researchers highlight various strategies to address the nutrition crisis, as developed by national task forces. These include focusing on nutrition security in federal nutrition assistance programs, such as SNAP and the Special Supplemental Nutrition Program for Women, Infants and Children. 

Moreover, they highlight the need to add “Food Is Medicine” services in healthcare, focus on federal labeling and regulatory approaches, advance nutrition science, incentivize private sector innovation and entrepreneurship and strengthen national coordination of nutrition-related efforts. 

The AHA has also rewarded 19 research projects to identify effective “Food Is Medicine” approaches to incorporate healthy food into health care delivery. 

Although the researchers found national progress in specific dietary components, they caution that US adults with an ideal diet quality were scarce. Moreover, the intake of dietary components “remains far from the dietary guidelines.” The highest proportion of participants with ideal diet quality was 2.92% among adults aged 65 or older.  

The study concludes that growing national rates of diet-related diseases, such as obesity and Type 2 diabetes, indicate a “need for substantial further improvements in diet quality before prevalence of these highly nutrition-sensitive conditions may begin to decrease.” 

By Jolanda van Hal