Misperception of diet quality among US adults: implications for cardiometabolic health promotion

Background: Diet is pivotal in preventing and managing cardiometabolic diseases. Our study aimed to describe the prevalence of poor diet quality and perceiving a poor diet as healthy and to determine individual-level factors associated with these groups. Methods: This cross-sectional study analyzed seven 2-year cycles of National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2018, which included non-pregnant adults between 20 and 85 years old, who completed a one-day 24-h dietary recall and dietary interview. Diet quality was measured using the American Heart Association (AHA) primary diet score, and perceived diet quality was based on NHANES questionnaire response. Results: Among 31,644 adults, the prevalence of poor diet quality was 47%. Male sex and smoking were associated with a higher risk of poor diet quality, while older age, higher levels of education, increased income, diabetes mellitus diagnosis, and increased vigorous activity levels were associated with a lower risk of poor diet quality. Among adults with poor diet quality (n = 14,952), 23% perceived their diet as healthy. In multivariable analysis, older age, higher education, and vigorous activity level were associated with a higher risk of perceiving a poor diet as healthy. Conclusions: Nearly half of US adults had poor diet quality based on AHA guidelines for cardiovascular health, yet nearly a quarter of them perceived their diet as healthy. This gap underscores the need for focused educational efforts and interventions in both healthcare and public health settings to dispel diet-related misperceptions and motivate the adoption of a healthier diet to address cardiometabolic health.