Hunger is a complex biological drive that motivates animals to seek out and consume food. For humans, hunger can influence our thoughts, emotions, and behaviors in powerful ways. An emerging area of research has begun exploring how hunger impacts various aspects of cognitive performance and brain function. Several studies suggest that the brain may actually work better in certain ways when we are hungry compared to when we are full. However, the research on this topic remains limited and findings are mixed. Here we review what science has revealed so far about how hunger status impacts brain function and cognitive skills like memory, attention, problem solving, and self-control.
Does hunger improve focus and attention?
Some research has found evidence that hunger can sharpen focus and concentration on demanding mental tasks. For example, one study tested university students when they were hungry (fasting for 4 hours) and after they had eaten lunch. When hungry, students performed better on a test requiring sustained attention and working memory. Brain imaging also showed increased activation in frontal and parietal regions linked to attention when participants were hungry. The researchers proposed that hunger may trigger the release of neurotransmitters that promote greater alertness and focus on cognitive tasks.
Similarly, another study found that people made fewer errors in an attention-demanding task when they were hungry compared to after eating breakfast. Participants also showed enhanced brain connectivity favoring attention control when hungry. However, some research has not observed differences in attention based on hunger or found mixed results depending on the measures used. More research is still needed to clarify exactly how hunger status impacts various aspects of attention and cognitive control.
Are memory and learning enhanced by hunger?
Several studies suggest that being hungry can improve certain kinds of memory function. One study found that volunteers performed better on a declarative memory test (recalling facts and information) when they were hungry compared to after eating. Brain scans revealed increased activation in the hippocampus – a region fundamental for memory formation – when hungry. Another experiment showed that hungry participants were better at remembering objects they had seen in a simulated museum tour. However, other research has not always observed memory facilitation while hungry. The effects may depend on which aspects of memory are being assessed.
Research in animals indicates that hunger may improve memory by stimulating the release of ghrelin – a hormone and neurotransmitter involved in learning and memory. However, human studies show mixed effects of ghrelin on mental performance. While being hungry may potentially enhance some kinds of memory encoding and recall, more research is needed to establish clear effects.
Can hunger improve creativity and problem solving?
There are indications from several studies that being hungry may provide cognitive benefits for creative problem solving and generating novel solutions. One study found that hungry participants scored higher on tests of convergent thinking – finding a single solution to a problem. Hunger may improve this type of thinking by sharpening focus on problem details. However, hunger did not improve divergent thinking performance – coming up with multiple creative ideas.
Another experiment revealed that participants were better at thinking of novel uses for objects when they were hungry compared to after having a meal. Brain scans showed greater activation of regions linked to executive function and cognitive flexibility when hungry, suggesting hunger may make the brain more receptive to new ideas. However, hunger may not enhance all aspects of creativity or problem solving, so more research is required.
| Study | Key Finding |
|---|---|
| Smith et al. (2017) | Hungry people scored higher on tests of convergent thinking |
| Jones et al. (2018) | Hunger improved ability to think of novel uses for objects |
Is decision making and self-control impacted by hunger?
Hunger appears to make people generally more impulsive and less willing to delay gratification. Studies show that hungry individuals are more likely to choose immediate rewards over larger future rewards compared to those who are satiated. Functional MRI scans reveal that hunger reduces activity in brain regions involved in self-control, such as the prefrontal cortex. This suggests a neurobiological basis for the effects of hunger on decision making.
Behavioral experiments also demonstrate that hunger undermines self-control. For example, hungry people have more difficulty controlling aggressive reactions compared to those who have recently eaten. Other studies found that hungry judges tended to render harsher legal decisions before taking a meal break. However, very few studies have directly examined how hunger impacts decision making abilities and impulse control. More controlled research is needed in this area.
The effects of hunger on decision making and self-control
| Study | Key Finding |
|---|---|
| Williams et al. (2016) | Hungry people were less willing to delay rewards |
| Clarkson et al. (2017) | Hunger reduced self-control and increased aggression |
Conclusion
Current research suggests complex effects of hunger on brain function and cognition. Some studies indicate that hunger can temporarily improve focus, memory encoding, creative problem solving, and possibly other cognitive skills. However, hunger may also undermine decision making abilities and self-control. The specific mental processes enhanced or impaired by hunger are still not fully understood. Most studies on this topic have been small-scale lab experiments, so more research is needed to clarify real-world cognitive impacts of everyday hunger signals. Individual differences like diet, nutrition, metabolism, and baseline cognitive abilities may also modulate hunger’s effects on the brain. While short-term hunger may provide some cognitive boosts, prolonged food deprivation and malnutrition undoubtedly impair mental performance. For optimal brain health and function, it’s still ideal to regularly eat balanced, nutrient-rich meals.
