Figure 3.

The figure schematizes how nocturnal light exposure, together with a misaligned feeding pattern with respect to the regular activity/rest rhythm, generate metabolic disruptions in nocturnal rodents and human subjects. Humans under nightwork schedules tend to invert by 180° their activity/rest rhythm, increasing nocturnal feeding and light exposure during the night. When receiving light at night, nocturnal rodents alter their feeding pattern increasing episodes throughout the day. These changes desynchronize pancreatic and liver circadian functions regulating nutrient balance and caloric usage/storage, mainly by reducing postprandial glucose tolerance, and decreasing glucose usage. As main outcomes of these alterations, increased basal glycemia, free fatty acids, and adipose tissue are generally observed. When chronically established, this misalignment between the circadian clock activity, its photic inputs, and behavioral/physiological/metabolic outputs can lead to metabolic syndrome and obesity.