Diet Quality: The Key to Healthy Eating

 The role of good nutrition in health and well-being has been established since early times, as far back as 1747, when the fact that scurvy could be prevented by eating citrus fruits was discovered. Historically, researchers have focused on the effects of individual nutrients or foods in isolation, as they relate to nutrition and chronic diseases. However, more recently nutrition scientists and researchers have looked at a more inclusive approach to diet and health using diet quality, because overall diet patterns may be a better predictor of disease risk than specific nutrients or individual foods.1 Diet quality focuses on the totality of what one eats and drinks; it examines healthy eating patterns as a whole, with the aim to bring about lasting improvements in individual and population health. In the literature, diet quality is used to investigate the association between foods and nutrients and chronic disease incidence and mortality.2

The federal government provides recommendations for optimal diet quality through the Dietary Guidelines for Americans. The 2015-2020 Dietary Guidelines for Americans provides guidance for choosing a healthy diet and focuses on preventing the diet-related chronic diseases that continue to affect our population.3 Its recommendations are ultimately intended to help individuals improve and maintain overall health and reduce the risk of chronic disease. Its focus is disease prevention, not treatment.3

Healthy eating is not about a list of “don’t eats” or depriving oneself of favorite foods. Rather, it is about a healthful lifestyle of consuming nutritious foods and beverages to improve the quality of the diet and health outcomes, such as to help reduce risk of diet-related chronic disease, including heart disease, type 2 diabetes, and cancer.

Evaluating the healthfulness of the diet is a great way that registered dietitian nutritionists (RDNs) can help to design suitable nutrition education materials appropriate for specific settings. To facilitate this process, the US Department of Agriculture’s (USDA’s) Center for Nutrition Policy and Promotion (CNPP) developed the original Healthy Eating Index (HEI). Subsequently, CNPP collaborated with the National Cancer Institute to provide various updates of the HEI to reflect the newest scientific evidence on diet and health, which resulted in three revisions, such as the HEI-2005, HEI-2010, and the current HEI-2015. Similarities among these three versions of the HEI are noted at: https://epi.grants.cancer.gov/hei/comparing.html.

The HEI-2015 measures how well people’s dietary behavior aligns with key dietary recommendations in the 2015-2020 Dietary Guidelines for Americans. The HEI-2015, an index that assesses the multidimensional components of the diet across the lifecycle, is useful in describing the diet quality of Americans and in identifying where focused efforts for improvements are warranted. Additional information on the HEI-2015 can be found on the CNPP website at: www.cnpp.usda.gov/healthyeatingindex. CNPP will offer continuing education credit for completing a self-study of this website.

To help RDNs understand how efforts in nutrition education may result in better HEI scores, describing factors relevant to the scoring of the HEI would be helpful. Thus, this article describes the characteristics of the HEI dietary components that impact the scoring system. It also summarizes how the HEI scores relate to diet quality and health outcomes.