**Background:** Noncommunicable diseases (NCDs) account for 71% (approximately 41 million) of annual global deaths, with cardiovascular diseases, respiratory diseases, and diabetes responsible for 17.9, 3.9, and 1.6 million deaths, respectively. Dietary quality is a key modifiable risk factor, yet its assessment has historically been dominated by a reductionist approach focused on individual nutrients rather than whole dietary patterns. While numerous dietary quality indices exist—such as the Healthy Eating Index (HEI) and Alternative Healthy Eating Index (AHEI)—these tools primarily emphasize biomedical factors and may not adequately account for the social and environmental contexts that shape food intake. The authors argue that incorporating such contextual factors is essential for translating dietary quality scores into effective, population-specific recommendations.
**Methods:** This is a critical review that synthesizes existing literature to propose a holistic conceptual framework for dietary quality assessment. The authors use the Diet Quality Index-International (DQI-I) as a focused example because of its design for cross-cultural applicability. The DQI-I assesses four major constructs—variety (0–20 points), adequacy (0–40 points), moderation (0–30 points), and overall balance (0–10 points)—and separates adequacy from moderation to distinguish between undernutrition and overnutrition. The review draws on the Giessen Declaration to broaden nutrition science into a more integrative discipline. The proposed framework includes three categories of factors: biomedical (e.g., health/disease status, genetics, anthropometrics), social (e.g., culture, socioeconomics, religion, food processing, meal patterns), and environmental (e.g., climate/seasons, pollution/contamination, land availability, food accessibility, food safety/regulation, topography).
**Key Results:** The review does not present original empirical data but synthesizes several key findings from the literature:
- Higher dietary quality index scores are generally associated with reduced risk of all-cause mortality, CVD mortality, and cancer mortality, though results for specific outcomes like CVD risk factors and abdominal obesity have been unclear.
- A meta-analysis of the DASH diet showed that even modest adherence scores are associated with lower all-cause and cause-specific mortality.
- Food insecurity affects approximately 2 billion people worldwide (1.04 billion in Asia, 676 million in Africa, 188 million in Latin America), while obesity affects over 650 million adults globally.
- In 2010, an estimated 2 billion illnesses and 1.09 million deaths worldwide were attributed to 22 foodborne diseases.
- The DQI-I was originally developed in 2003 for a cross-national study comparing the United States and China, addressing the lack of a valid cross-national dietary quality measurement tool.
- The paper presents two hypothetical examples of the holistic assessment process: (1) a community-level example in a rural, low-income, low-access area (using the USDA Food Access Research Atlas), where limited protein variety and reliance on processed foods may reduce adequacy and moderation scores; and (2) an individual-level example of a person with lactose intolerance living in a northern geographic area during winter, where low Vitamin D intake and reliance on canned vegetables may affect adequacy and moderation scores.
**Clinical Implications:** The authors propose a three-step Holistic Dietary Quality Assessment Process: (1) identify the purpose of the assessment and select an appropriate dietary index; (2) select relevant contextual factors (biomedical, social, or environmental); and (3) analyze how each contextual factor influences specific index components (variety, adequacy, moderation, balance). This framework is intended to help practitioners identify barriers to dietary quality that are within or outside a patient's control, set realistic 'ceilings' for achievable dietary quality, and tailor post-assessment recommendations accordingly. For public health officials, the framework could guide policy interventions such as reducing sales taxes on fresh produce or creating pop-up farmers markets in food deserts. The authors emphasize that this approach could strengthen evidence-based nutrition practices by improving understanding of individual and population-level goals, preferences, accessibility, and resources. They also note that the framework could be applied to other dietary indices beyond the DQI-I, and that separate tools assessing social and environmental factors could be used alongside existing indices.