Short-term sleep restriction does not increase spontaneous food intake in normal-weight men

Abstract

Background: The role of sleep in body's energy homeostasis and the pathogenesis of obesity is presently widely discussed. Epidemiological data show a clear association between short sleep duration and increased body weight. Furthermore, a previous experimental study showed increased feelings of hunger and appetite after short-term sleep restriction. Here, we assessed the influence of short-term sleep restriction on food intake in healthy men. Methods: Fifteen healthy normal-weight men were studied on 2 conditions separated by at least six weeks: (i) after two consecutive nights of regular 8 hours of sleep, and (ii) after two nights of only 4 hours of sleep in the second half of the night, subjects had to stay in our laboratory under time deprivation conditions until the following evening. During the whole day participants were offered a large breakfast and snack buffet and could order warm dishes whenever they wanted. Symptom ratings were assessed every hour and food intake was monitored continuously. Results: After sleep restriction feelings of fatigue were increased throughout the day in comparison to the regular sleep condition (P=0.001 for ANOVA main effect 'sleep'). There were no differences in appetite and hunger ratings between the two conditions (P>0.62 for ANOVA main effect 'sleep'). Also, total energy intake did not differ between the sleep restriction and regular sleep condition (4013±268kcal vs. 4006±284kcal, P=0.98). Furthermore, we could not detect any differences in the intake of different macronutrient components between the two conditions. Conclusion: Our data show that in normal weight men short-term sleep restriction does not increase ad libitum total food intake in an experimental setting of time deprivation. This result contrasts previous findings of increased hunger and appetite after short term sleep restriction. However, our finding does not exclude that food intake is increased during longer periods of short sleep duration thereby promoting the development of obesity.