A recent study has found that adolescents who are overweight or obese are more susceptible to cognitive impairments following sleep restriction compared to their peers with healthy weight. This research was published in JAMA Neurology.
Previous research has established a link between pediatric obesity and cognitive difficulties, such as impaired executive function. Poor sleep has also been associated with increased adiposity (having a lot of body fat) and impaired cognition. However, the mechanisms underlying these associations have remained unclear.
Led by Lindsay M. Stager, researchers from the University of Alabama at Birmingham aimed to investigate the effects of adiposity and sleep on adolescent cognitive function.
Stager and colleagues began by recruiting 61 adolescents aged 14 to 19 years.Questionnaires were administered on demographics and eating behaviors. Following this, adiposity was measured using body mass index (BMI) as well as total body fat percentage (TBF%), which categorized the participants into having a healthy weight (31 adolescents) and being overweight or obese (30 adolescents).
The study involved two sleep conditions: adequate sleep, with an average duration of 8 hours and 54 minutes, and restricted sleep, with an average duration of 4 hours and 12 minutes. After each sleep condition, the adolescents underwent cognitive assessments to evaluate several aspects of their cognition.
This included global cognition (overall indication of how well the brain functions), fluid cognition (ability to solve new problems and use logic in new situations), cognitive flexibility (brain’s ability to handle thinking about multiple concepts at once), working memory (the brain’s ability to temporarily hold and work with information), episodic memory (memories of specific events in life), attention (ability to focus on a task without getting distracted), as well as processing speed (how quickly the brain can understand and react to information).
The findings revealed that restricted sleep led to poorer global cognition, fluid cognition, and cognitive flexibility in adolescents who were overweight or obese, compared to adequate sleep. In contrast, no significant differences in cognitive performance were observed for adolescents with healthy weight between the two sleep conditions.
Adolescents who were obese or overweight also had significantly lower attention scores following restricted sleep when compared to their peers with healthy weight who also had restricted sleep.
No differences were evident following adequate sleep for either group.
Stager and colleagues noted the significance of their findings: “cognitive impairments predict increased symptoms of anxiety and depression, bullying, decreased adherence to medical recommendations, poorer academic achievement, less healthy food choices, and many other aspects of daily living. Further, the cognitive impacts of sleep restriction can be additive when sleep is restricted across multiple nights. Thus, if adolescents experience chronic sleep restriction, which may commonly occur during the school week, the above effects may be compounded.”
Overall, the study underscores the importance of adequate sleep for adolescents, particularly those with overweight or obesity.
However, the study had some limitations. For instance, the at-home sleep conditions may have introduced variability in participants’ sleep duration and environment.
The study, “Effect of Sleep Restriction on Adolescent Cognition by Adiposity”, was authored by Lindsay M. Stager, Caroline S. Watson, Edwin W. Cook III, and Aaron D. Fobian.
