The scale used, the Alternate Healthy Eating Index 2010, is the sum of 11 components, and it has been show to predict chronic disease, markers of inflammation, and death. Optimal diet quality on the index is 110, and right now we're below 50.
Hu later called the growing gap between the rich and poor “disturbing.” That gulf is really the critical takeaway of this study. There can be no tenable “overall improvement” when there is growing disparity around a point so critical to preventive medicine, or when there is deterioration among any such sizable marginalized population.
Walter Willett, chair of the department of nutrition at Harvard School of Public Health, said in a press statement that the widening gap is related to income and education and “presents a serious challenge to our society as a whole.” Hu also drew a parallel between diet quality and income trends, noting, “After the financial crisis, the top one percent is doing very well—actually doing better, but the people in the low socioeconomic status groups are doing worse."
Access to high-quality food is also important from a public health point of view because in low socioeconomic status groups, the burden of diet-related diseases is disproportionately high. “With deterioration in diet quality over time,” Hu said, “this may actually even increase disparities in obesity and other diet-related conditions.”
The research paper is not wanting for a politicized call to action. The authors write: “Collective actions, such as legislation and taxation, that aim toward creating an environment that fosters and supports individuals' healthful choices are more effective at reducing dietary [disease] risk factors than actions that solely depend on personal responsibility.”
“We need to intensify efforts to educate the public about the role of diet in prevention of disease, and also implement policies that can help to improve the food environment,” Hu emphasized. Lack of affordable and accessible healthy foods among low socioeconomic status groups, especially in minority and inner city populations, he noted, has important implications for federal nutrition programs.
The U.S. government has tried to address this disparity with the Supplemental Nutrition Assistance Program (SNAP), which receives almost $80 billion in federal funding annually. That is distributed among 47 million Americans who receive a monthly average of $133 per person. That money can be spent on any type of calorie, with no incentive to buy healthy food. Nutritionists tend to put “junk food” in quotes as an objection to things like Pixy Stix bearing the moniker “food” at all. (There are calories in paper, cotton, toenails, and Pepsi—should that qualify them as food?)
"SNAP can have a big influence with better incentives to purchase healthy foods like fruits, vegetables, and whole grains rather than soft drinks and highly processed quote-unquote junk food,” Hu said. “I think the programs should put more emphasis on quality of diet rather than just quantity. This is an area where the combination of nutrition education and financial incentives can really shape people's attitudes and behaviors.”