Examining Demographic Variables Associated with Fruit and Vegetable Intake and Skin Yellowness

Background/Objectives: Skin yellowness measured using reflectance spectroscopy can be used as a proxy for 'skin carotenoid' concentration and as a valid estimate of fruit and vegetable intake. However, the association between different ethnic backgrounds, age, sex and self-reported skin colour on skin yellowness is yet to be explored. Methods: This exploratory cross-sectional study used a convenience sample to assess the relationship between skin yellowness (b*), measured using skin reflectance spectroscopy, and fruit and vegetable intakes across different age groups, sex, self-reported Caucasian and Asian ethnicities and self-reported skin colour. Recruited adults were aged ≥18 years who self-reported as Caucasian or of Asian ethnicity (N = 137). Data were collected on skin L*, a*, b* colours using skin reflectance spectroscopy, height, weight, body composition, waist circumference, demographic variables (e.g., age, sex, self-reported skin colour), and dietary intake measured using the online Australian Eating Survey^® (AES^®). Multiple linear regression models were used to investigate factors associated with the dependent variable, skin yellowness (b*). Results: Participants were on average 38.6 (SD = 17.7) years of age, self-reported as female (61%), Caucasian (77%) and met the recommended fruit intake of two serves/day (mean = 2.1, SD = 1.5) but not the recommended vegetable intake of five to six serves per day (mean = 4.4, SD = 3.1). There were significant associations between skin yellowness (b*) and several independent variables, including combined fruit and vegetable intake, total carotenoid intake, body fat percentage and self-reported skin colour. Conclusions: This study adds additional support for using skin yellowness as a proxy for fruit and vegetable intake when adjusting for self-reported skin colour, age and sex.