Use of the Veggie Meter® as a tool to objectively approximate fruit and vegetable intake among youth for evaluation of preschool and school-based interventions

Background Reflection spectroscopy is an emerging, non-invasive objective measure used to approximate fruit and vegetable intake. The present study aimed to use a reflection spectroscopy device (the Veggie Meter (R), Longevity Link Corporation, Salt Lake City, UT, USA) to assess skin carotenoid status in preschool, middle- and high-school students and to examine associations between skin carotenoids and self-reported dietary intake. Methods In Autumn 2018, we used the Veggie Meter (R) to assess skin carotenoids and age-appropriate validated dietary assessment measures to approximate fruit and vegetable (FV) intake. Preschool participants completed a previously validated pictorial liking tool using an iPad (Apple Inc., Cupertino, CA, USA). Middle-school participants completed selected questions from the validated School Physical Activity and Nutrition (SPAN) (Michael & Susan Dell Center for Healthy Living, University of Texas, Austin, TX, USA) questionnaire regarding frequency of their FV and beverage intake on the previous day, with additional questions about physical activity. High-school participants' FV intake was assessed using the Fruit and Vegetable Screener (National Cancer Institute, Bethesda, MD, USA). Spearman correlation coefficients were used to determine bivariate associations between measures of dietary intake and Veggie Meter (R)-assessed skin carotenoid levels. Results Mean (SD) Veggie Meter (R) readings were 266 (82.9), 219 (68.1) and 216 (67.2) among preschool, middle- and high-school students. There was an inverse association between soda intake and Veggie Meter (R) readings (r = -0.22, P = 0.03) among middle-school students; and a positive association between daily fruit intake and Veggie Meter (R) readings (r = 0.25, P = 0.06) among high-school students. Conclusions The Veggie Meter (R) comprises a promising evaluation tool for preschool and school-based nutrition interventions.