Fig. 1: Solar exposure enhances the energy intake and metabolic profile of men compared to women.
From: Food-seeking behavior is triggered by skin ultraviolet exposure in males
a, Dot plot of the monthly energy intake (Kcal per day), from 1999 to 2001, of 2,991 men (cyan blue) and women (pink) (top). Midline represents the median. Data are presented as mean ± SD. Men’s energy consumption was significantly higher during the summer (2,188 Kcal versus 1,875 Kcal, p < 0.001), while energy consumption in women remained constant (1,507 Kcal versus 1,475 Kcal, p = 0.795). Lower panel: Monthly average of direct solar radiation (KJ/m); yellow intensity reflects the radiation strength. b, Energy intake (Kcal per day) of men (top) and women (lower panel) in winter (October to February) and summer (March to September). Each individual participant is represented by a dot (summer: n = 556 men, n = 1,045 women; winter: n = 774 men, n = 616 women). Data are presented as mean ± SD. For the statistical analysis, unpaired t-test assuming unequal variance with Welch’s correction was performed. We found that men consume more calories during the summer than in the winter (p < 0.001), while the calorie intake of women was similar (p = 0.27) between the two seasons, demonstrating that only men are affected by the seasonal change. c, Proteomics analysis, shown as Proteomap, illustrates the functional categories of men (top) and women (bottom) blood plasma proteins before (left panel) and after (right) exposure to 2,000 mJ/cm2 solar UVB. Data presented in each polygon represents proteins in a single KEGG pathway with >2 fold change (n = 5 biologically independent human subjects per condition). d, Volcano plot of differentially expressed proteins in men (before/after solar UVB exposure) by log2 fold change; metabolic-related proteins are marked orange. e, Radar map of Gene Ontology enrichment of differentially expressed proteins identified by mass spectrometry analysis of blood plasma proteins from mice after UVB (50 mJ/cm2) or mock UVB (control) irradiation (n = 3 biologically independent mice per condition).
