Objectives: Little is known about cancer survivors' self-perception of their dietary quality compared with their measured diet quality and how those perceptions may influence their actual diet. This study aimed to fill this gap using national large datasets.
Methods: National Health and Nutrition Examination Survey (NHANES) data from 2005 to 2014 were used. The healthy eating index (HEI) based on 24-h dietary recall was used to measure diet quality. Logistic regression models were fit to examine the influence of the misperception of eating healthiness on diet quality.
Results: The agreement between self-perceived and actual diet quality was low (Kappa = 0.06, 95% CI: 0.02, 0.09) among cancer survivors. Over-rating diet quality was associated with a 5.39 lower total HEI score (P < 0.0001), 1.00 lower HEI score for empty calorie intake (P = 0.0028), 0.15 lower score for vegetable intake (P = 0.108), and 0.29 lower score for fruit intake; under-rating one's diet quality was associated with a 7.12 higher total HEI score (P < 0.0001), 2.57 higher HEI score for empty calorie intake (P < 0.0001), 0.02 higher score for vegetable intake (P = 0.904), and 0.84 higher score for fruit intake (P = 0.001). Our multinomial regression estimates suggested that each 10-year increase in age was associated with an increase in the odds of being an over-rater vs. a correct-rater (OR: 11.4, 95% CI: 10.01, 10.2). Hispanics were more likely than non-Hispanic whites to over-rate their diet quality (OR: 1.792, 95% CI: 1.062, 3.024).
Conclusions: Tailored nutrition interventions and guidance aimed at reducing the divergence between self-assessed and actual diet quality have the potential to improve cancer survivorship and narrow racial/ethnic and socioeconomic disparities.