Figure 5. Diet-linked skin reflectance changes track common carotenoids.

Solid black line - Spearman correlation coefficients (_{ρ Δ reflectance vs Δ diet}) of the relationships between fruit and vegetable consumption change (from week 0 to 6) and average skin reflectance change. Dashed bold line shows the mean absorption spectra [cm⁻¹ (mg/ml)⁻¹] for three common carotenoids, which are individually plotted (blue rhombi - α-carotene, orange triangles - β-carotene and red circles - lycopene).