Sleep restriction leads to increased activation of brain regions sensitive to food stimuli.
Level 2 - randomized trial
Individual randomized crossover trial
PubMed 22357722 · doi:10.3945/ajcn.111.027383
What was done
Thirty healthy, normal-weight men and women (BMI 22-26 kg/m²) were recruited, with 26 completing a two-phase inpatient crossover study comparing 4 hours/night (restricted sleep) versus 9 hours/night (habitual sleep) in bed for 6 days per phase. On day 6 of each phase, functional magnetic resonance imaging (fMRI) was conducted in the fasted state during presentation of food stimuli.
What was found
The abstract reports no numerical values or statistical effect sizes. Overall neuronal activity in response to food stimuli was greater following restricted sleep than habitual sleep, with relative activation increases observed in reward-related areas including the putamen, nucleus accumbens, thalamus, insula, and prefrontal cortex.
Why it matters
This study provides neural evidence that sleep restriction enhances brain reward-region responsiveness to food cues in healthy adults. This offers a mechanistic explanation for how short sleep duration may drive increased appetite and overeating.
Limits
The sample size was small (26 completers) and limited to healthy, normal-weight adults in a controlled inpatient environment. The abstract does not report numerical data, variance, or actual food intake and caloric consumption.