Sleep deprivation and food choice: effects of cognition and preference

Abstract

Background: Sleep deprivation has been shown to lead to decreased cognitive functioning (i.e. inhibitory control). Furthermore, sleep deprivation has been linked to overweight and increased unhealthy food intake. This study tries to determine whether this relation between food intake and sleep deprivation is due to decreased cognition, a changed food preference or both. Methods: Using two types of tasks (choose the preferred or non-preferred stimulus) on the same stimuli after normal sleep and a night of partial sleep deprivation (4 hours less than usual), the response times to these stimuli in 36 participants in a 2x2 within subjects design were used to investigate the question above. Findings: For non-food stimuli response times are only influenced by type of task, not by amount of sleep; when choosing the non-preferred stimuli participants are slower due to translating their preferred choice to a response to the non-preferred stimulus (F(1,35) = 18.708, p < .0001), but this does not depend on sleep. The response times to food stimuli are in general slower than for non-food items, and only show a switching cost in the normal sleep condition, not after sleep deprivation (sleep x task interaction, F(1,35) = 4.158, p = .049). Moreover, after sleep deprivation the proportion of unhealthy choices in food stimuli changes independent of type of task (F(1,35) = 6.739, p =.014). Discussion: The results together make it tempting to suggest that both a changed preference and a slowed down cognition play a role in choosing for unhealthy food.