To Eat or Not to Eat: An Investigation of Meal Skipping on Cognitive Functioning

Inadequate nutrition has been shown to adversely impact brain development and cognitive functioning (Pollitt, Lewis, Garza, & Shulman, 1983). Unhealthy eating practices are frequently formed in college-aged samples; individuals in this age-range may be at risk for developing dangerous dieting behaviors (Neumark-Sztainer, Butler, & Palti, 1995). Studies examining the acute impact of eating regular meals on cognition have reported inconsistent findings, necessitating the exploration of moderators to possibly help explain findings. This study sought to clarify the impact of skipping lunch on cognitive ability and interoceptive awareness in college-aged students by including eating restraint as a moderator. Participants were randomized to a ‘lunch’ condition (consuming a 638-calorie shake) or a ‘lunch omission’ condition (consuming a 48-calorie shake). Prior to shake consumption, participants completed demographic questionnaires and reported levels of affect, satiety and fatigue. After a controlled wait period of two hours, participants completed a neuropsychology battery, which assessed short-term memory , long-term memory, working memory, attention, processing speed, set shifting, eating disorder symptomology, depression, and anxiety.

Results revealed that participants in the lunch condition had better short-term memory performance relative to participants in the lunch omission condition. No differences were found between groups for long-term memory, working memory, attention, or processing speed. Regressing set shifting speed on the manipulation, eating restraint scores, and their interaction revealed a trending interaction term: Individuals in the no-lunch condition had faster set shifting speed than individuals in the lunch-condition, but only for those with lower levels of eating restraint. Lastly, regressing change in satiety on the manipulation, eating restraint scores, and their interaction, revealed a significant interaction term: Individuals in the lunch condition reported higher satiety than individuals in the no lunch-condition, but only for those with lower levels of eating restraint. There was no evidence to support differences in affect or fatigue between conditions. Implications of these findings, limitations to consider, and future research directions are discussed in the body of the paper.