Crux of Can lack of sleep contribute to obesity? by John Briffa:

  • Sleep deprivation affects hunger and satiety hormones: “sleep deprivation has been found to boost levels of the hormone ghrelin that stimulates appetite, [and] lower levels of the hormone leptin [that] suppresses appetite [and] speeds the metabolism.”
  • A new study showed that people feel hungrier when they are sleep deprived, and that their brain shows more activity in the anterior cingulate cortex – a brain structure that influences the sense of appetite and hunger.