Fig. 1.

Body mass, fat pad mass, and glucose tolerance were altered in mice exposed to bright or dim light at night. (A) Weekly body mass for mice throughout the study (*P ≤ 0.05 when LD differs from both LL and DM groups; ^&P ≤ 0.05 between all groups). Mice exposed to light at night had elevated body mass beginning 1 wk after placement in experimental light conditions and continuing throughout the remainder of the study. (B) Body mass gain and epididymal fat pad mass differed among groups at the conclusion of the study, suggesting increases in body mass may be caused by changes in body fat composition. (C) Mice exposed to either DM or LL had reduced glucose tolerance, and DM and LL mice failed to recover blood glucose as rapidly as LD mice (*P ≤ 0.05 when LD differs from both LL and DM groups; ⁺P ≤ 0.05 when glucose level is higher in the DM group than in the LD group). (D) Body mass at the time of the GTT correlated positively with final blood glucose levels.