A disease mechanism driving the clinical symptomology of the Night Eating Syndrome (NES) may be a metabolome, polyunsaturated fatty acids in particular, disrupted in its oscillations throughout the course of day and night. Blood and stool samples will be repeatedly taken during a 3-night/2-day protocol from NES patients and healthy controls with lights dimmed to 20 lux and time cues removed. Body core temperature and physical activity during the study will be monitored continuously.