Dietary Quality and Diet-Related Factors Among Emerging Adults (18-23 y) in the United States Are a Cause for Concern: National Health and Nutrition Examination Survey 2015-2018

Background: Poor dietary quality is a risk factor for diet-related chronic disease and suboptimal nutritional patterns often begin early in the life course. Although the dietary intakes of young children, adolescents, and middle-aged and older adults are well established, much less is known about emerging adults, who represent a unique time point in life, as they are undergoing significant changes in food environments, autonomy, finances, and caregiver and parental involvement. Objectives: This study aimed to examine dietary quality, as assessed via the Healthy Eating Index (HEI), by demographic, socioeconomic, and health-related characteristics among emerging adults (18-23 y) in the United States who participated in the 2015-2018 National Health and Nutrition Examination Survey (NHANES). Methods: NHANES data were collected via a household interview and 2 24-h dietary recalls (24HR). Usual dietary intakes from the 24HRs were approximated using the multivariate National Cancer Institute Method to compute mean HEI-2015 overall and component scores (range: 0-100; higher scores indicating higher dietary quality). Results: Overall dietary quality among emerging adults (HEI-2015: 50.3 +/- 1.3) was significantly lower than other adults (>= 24 y) (HEI-2015: 56.3 +/- 0.5; P < 0.0001) in the United States, with differences primarily driven by lower intakes of whole fruit, vegetables, and whole grains and higher intakes of sodium, refined grains, and saturated fat. Few differences in HEI-2015 scores were noted across population subgroups by sex, food security, family income, and food assistance program participation, except for added sugar; intakes of added sugar were significantly higher among women, food insecure, and food assistance program participants than those in their counterparts, respectively. Conclusions: Dietary quality is poor among emerging adults in the United States and persists across all population subgroups, suggesting a significant need for tailored public health interventions to improve dietary quality among this population. Future research investigating to what extent emerging adults prioritize healthful behaviors and exploring other indicators for identifying nutritionally vulnerable subgroups may be impactful for identifying disparities among this life stage.