Study: Your Nighttime Food Cravings Are Genetic

Ever wake in the middle of the night craving a cheeseburger or maybe come of that leftover pizza that’s in the fridge?  Does it happen to you a lot?  A new study says that these nighttime food urges may be genetic.

The study, conducted at the Salk Institute for Biological Studies, focused on a pair of genes that normally keep eating schedules in sync with daily sleep rhythms. If those genes are mutated, they say it may play a role in so-called night eating syndrome.

The study’s findings were broken down by

The inspiration behind the research was a decade’s old discovery of a particular mutation in a protein called PER2 which causes an inherited sleep disorder. The mutation is in an area of the protein that can be phosphorylated—the ability to bond with a phosphate chemical that changes the protein’s function. Humans have three PER that play a role in the daily circadian clock and all containing the same phosphorylation spot. The scientists wondered whether mutations in the equivalent area of PER1 would have the same effect as those in PER2 that caused the sleep disorder.

So, the Salk scientists joined forces with a Chinese team led by Ying Xu of Nanjing University to test these mutations in mice. They bred mice without mouse period genes and added human PER1 or PER2 with a mutation. The mice with mutated PER2 had sleep defects but the mice with a PER1 mutation, had no issues with their sleep-wake cycles but surely enough did have problems with their eating schedule.

The mice with the PER1 defect ate earlier than other mice—causing them to wake up and snack before their sleep cycle was over—ate more food throughout their normal waking period, had lower protein levels during the sleeping period, higher levels during the waking period, and a faster degradation of protein whenever it was produced by cells.

Many doctors and researchers over the years have said night eating syndrome isn’t real.  The Salk scientists say their research suggests there is a genetic basis for it.