Reflection Spectroscopy-Assessed Skin Carotenoids Are Positively Associated With Diet Quality and Inversely Associated With Food Security Among Participants in a Community-Based Nutrition Intervention.

OBJECTIVE: Examined convergent validity of reflection spectroscopy-assessed skin carotenoid scores (SCS) by examining associations between SCS and (1) self-reported fruit and vegetable (F&V) intake, (2) Healthy Eating Index scores derived from 24-hour recalls, (3) food security, (4) self-efficacy for F&V intake, and (5) barriers to F&V intake. DESIGN: Cross-sectional study PARTICIPANTS/SETTING: We analyzed baseline data from adult participants (n = 217) who were recruited as part of an intervention study focused on mobile markets. MAIN OUTCOME MEASURES: Skin carotenoid scores were assessed using the Veggie Meter. Self-reported F&V intake was assessed using items from the Behavioral Risk Factor Surveillance System and the Nutrition Data Systems for Research (NDSR). Healthy Eating Index scores were derived from 24-hour recalls, and self-efficacy, barriers to F&V intake, and food security were measured using validated scales. ANALYSES: Pearson product-moment correlations and regression analyses were used to examine cross-sectional associations between SCS and diet, diet quality, and psychosocial measures. We assessed differences in skin carotenoids by level of food security with analysis of variance and a mixed model. RESULTS: . There were positive correlations between SCS and (1) Behavioral Risk Factor Surveillance System-assessed vegetable and fruit intake per day (r = 0.15, P = 0.03 and r = 0.20, P < 0.01, respectively), (2) NDSR-24 hour recall F&V servings (r = 0.24, P < 0.01, and r = 0.23, P = 0.01, respectively), (3) NDSR-24 hour recall carotenoids (r = 0.20, P = 0.03): (4) Healthy Eating Index scores (r = 0.30, P < 0.01), and (5) Self-efficacy for eating F&V (r = 0.15, P = 0.04). There was an inverse association between SCS and food security such that having low food security compared with high food security was associated with lower SCS scores (low vs high 232.6 ± 82.7 vs 293.5 ± 104.2, P = 0.002), which was attenuated when controlling for age, income, and race. CONCLUSIONS AND IMPLICATIONS: Skin carotenoid scores may be a useful biomarker of diet quality. Future studies could examine relationships between SCS, diet quality, and food security in additional populations.