A comparison of feeding to cephalic stimulation on postprandial sleepiness.
Level 3 - non-randomized controlled study
Controlled crossover study without explicit mention of randomization in the abstract
PubMed 9661987 · doi:10.1016/s0031-9384(98)00025-0
What was done
Nineteen healthy adults (11 men, 8 women without gastrointestinal disease or sleep disorders) participated in a 2-day crossover study comparing the consumption of a standardized solid meal to sham feeding (chewing and expectorating). Subjects took a baseline nap at 1600 hours, received the meal intervention at 1700 hours, and underwent polysomnographic monitoring during naps at 1730, 1800, and 1900 hours to determine objective sleep onset latencies.
What was found
Sleep onset latencies differed significantly between the actual ingestion and sham feeding conditions only at the 1800 hours nap (one hour postprandial), showing a transient decrease in sleep onset latency following meal ingestion. The abstract does not report specific numerical values, means, standard deviations, or p-values.
Why it matters
This indicates that postprandial sleepiness is driven at least in part by gastrointestinal or post-ingestive mechanisms rather than cephalic sensory stimulation alone.
Limits
The sample size was small (n = 19). The abstract does not specify whether condition order was randomized, does not report meal composition or exact numerical sleep latency values, and was limited to a two-hour postprandial window.
Cited by
- supports Eating a meal promotes sleepiness in many individuals.