The vegetable intake of Japanese has been insufficient against the target (350 g/day) for decades. We believe that one of the reasons for this is the lack of opportunity to know one's own vegetable intake correctly, therefore we developed a device to estimate vegetable intake by measuring skin carotenoid levels easily and non-invasively. For measuring skin carotenoid levels, a sensor which could detect a specific range of wavelength of light reflected from the skin was used. Multiple studies, including ours, have suggested that skin carotenoid levels measured by the sensor show a statistically significant positive correlation with blood carotenoid concentrations and vegetable intake calculated by dietary surveys although the correlation between skin carotenoid levels and vegetable intake was relatively low. The measured value has been suggested to associate with the results of several items of health checkup, especially those related to metabolic syndrome such as body mass index, visceral fat area, blood pressure, fasting blood sugar, and serum lipid, etc. It has also been found that regular measurement of skin carotenoid levels contributes to habituation of vegetable intake behavior. In the near future, we expect that this kind of measurements will become widespread in the field of dietary guidance.
